ALFRED SUNG

Oh, it's menswear everywhere for women. Or so say the sartorial seers from Seventh Avenue to SoHo. But to the north, in the chilly confines of Canada, which have never been a piping hotbed of fashion, comes menswear with a difference: Alfred Sung sportswear.

While the name is not yet garnering great nods of recognition from the fashion-minded this side of the St. Lawrence, Alfred Sung has rapidly become the darling of Canada's fashion industry. In a country that has produced more rugged outerwear than fashion superstars, Sung is cutting an original swath.

In the five years that this Shanghai-born, Paris-trained designer has been creating cool, classic clothes in his Toronto studio, Sung has catapulted from obscurity to stardom. In Canada's nearly $6 billion-a-year fashion industry, Sung is considered the reigning designer. Sales of his elegant but reasonably priced sportswear have doubled every year since 1979; by 1985 they are expected to top the $60 million mark.

Observers who sing Sung's praises are calling him Canada's Yves Saint Laurent.

''His look is always right,'' says one Toronto fashion editor. ''He is more international (than American designers). He's more like Saint Laurent that way.''

Sung has also won raves from the Canadian trade papers and newsmagazines and from such high-profile women as Margaret Trudeau and Mila Mulroney, the wife of the new prime minister, Brian Mulroney. Across the border, Saks Fifth Avenue named Sung one of the top 10 new designers of 1981.

''Sung has put the Canadian fashion industry on the map,'' says Erica Wilson, a buyer for Eaton's, one of Canada's largest department store chains.

''Canada used to be known largely for its outwear,'' says Elizabeth Watson, editor of Toronto's Style magazine, ''but this has changed enormously since Sung and other designers like Wayne Clark are finally getting recognized. This side of the business is really taking off.''

By usual designer standards, Sung's clothes are not expensive - prices range from $85 to $450 or even less in the more casual Sungsport line. Most observers categorize his sportswear as understated chic, classics with a fillip of panache. A Neiman-Marcus executive describes it as ''a tremendous amount of styling at responsible and reasonable prices.''

Sung is said to design with career women in mind, creating understated, wearable clothes that are popular with customers of the ''middle-weight, middle-age, and middle-income'' bracket, according to one fashion-watcher. Despite Sung's early training as an artist, his design attitude has been described as ''fairly pragmatic,'' even ''computerized.'' Some have called him occasionally ''passionless'' and more of a business success than fashion innovator. Indeed, pragmatism, in both the designing and selling of the clothes, figures heavily in his success.

Fundamental to the continued growth of his business are Sung's aggressive marketing plans, which observers say emulate American designer strategies. From an initial 30-piece collection Sung designed for Toronto garment manufacturers Saul and Joseph Minram in 1978, the naturalized Canadian has followed the lead of such successful US designers as Ralph Lauren and Bill Blass: accessories, accessories, accessories. Sung's current collection sports 200 pieces, including coats and evening wear, spread between the designer's two divisions: Alfred Sung and Sungsport. Already gloves, belts, and hats have been added to the collection , and the possibility exists for a tidal wave of more Sung designer wear: menswear, children's clothes, perfume, and linens.

But by far the biggest marketing maneuver employed by Sung and his partners the Minrams, who together constitute the Monaco Group, is their attempt to expand beyond the limited population of Canada and garner an even larger share of the US market. By 1985, a projected 20 Alfred Sung shops will dot the United States. Three have already opened, one in Boston's chic Copley Place, another in Washington's upscale Georgetown Park, and a third in New Jersey.

''Why keep it a secret?'' says Saul Minram, referring to the company's vigorous expansion plans. Already the group earns a third of its $44 million business in the US.

Nonetheless, some US markets are far from sewn up. While such tony American stores as Bloomingdale's, Neiman-Marcus, Lord & Taylor, and Bergdorf Goodman carry the Sung label, not one has given him an in-house boutique, although Macy's will open a Sungsport shop next February. And such fashion tomes as Women's Wear Daily and Vogue, while frequently sporting Sung ads, have not yet devoted large chunks of editorial copy to him.

But a recent showing of Sung's fall collection in the Boston area revealed wearable, affordable classics. Not as sharply tailored as American designs, Sung's skirts, blouses, jackets, and coat dresses are fluid, yet anchored by crisp, tight details: top-stitching, crossed tab belts, tiny pewter-colored snaps, leather plackets, and arrow-straight knife pleats that seem to be Sung's signature.

Unlike British designers who strive to stave off winter's chill with the thickest of wools, Sung uses few bulky tweeds, preferring to layer lightweight wools, including jersey, Viyella, angora, and the occasional piece of gabardine - fabrics that add to the look of comfort.

Too, Sung's color scheme is easy on the eye. This fall he shows solid colors in muted tones of steel, olive, cream, and stone. Lest this strike the wearer as too staid, he throws in a vibrant purplish blue. Paired with cream silk blouses, it looks as cool as a blueberry sundae.

When the slight, mustachioed designer finally appeared on the arms of his models to acknowledge the applause at the end of the show, the admiration was a two-way street.

''Thank you for wearing my sweater,'' he said politely to a young woman in a nubby blue-and-white number, just minutes before Sung, natty in white tennis shoes and white trousers, was whisked away in a steel gray Honda.