If you need a haircut, you must get one. If you are a policeman, you must salute the comrade you are about to book. And if you are like most Peking residents, you must stop spitting in the street.
At least that's the idea behind China's ''civic virtues month,'' launched each March to counteract the ''dirt, disorder, and discourtesy'' to be found in most of China's overcrowded cities.
A range of fines from 5 cents to $5 - a hefty slice of the average Chinese income - has been introduced for the month to encourage people to use crosswalks , ride their bikes on the right side of the road, and use a handkerchief instead of the sidewalk to clear their throats.
According to China's nominal head of state, Li Xiannian, who oversees such campaigns, ''This year's civility and courtesy month movement . . . should encourage high quality services, establish good order, and create a fine environment.''
Unlike many other mass movements in China's past, the Chinese leadership has clearly spelled out the requirements of civic virtues month.
''In commercial catering and transport services, hospitals and clinics, cinemas and theaters, stadiums and gymnasiums, post and telecommunications offices, scenic spots and historical sites, parks in cities and towns, busy streets, all cadres, workers, and staff members must improve their standard of professional ethics, increasing their spirit to serve the people, and turning their posts into civility show windows,'' President Li declared before the campaign began.
The campaign is aimed in particular at Peking's 390,000 Young Pioneers - China's equivalent of Boy Scouts. Red-scarfed Pioneers can be seen around the city helping people across busy roads, sweeping paths, and stretching on their toes to polish the windows of the red and yellow sentry boxes that dot intersections.
Although it is a nationwide drive, this year's campaign is centered in the capital, Peking, where big national day celebrations are being planned for Oct. 1 for the first time since the 1970s. (In 1971, reports of an attempted coup by then Defense Minister Lin Biao led to the cancellation of all parades and public exercises.)
The month of sprucing also means that Peking, plagued by dust storms that are normal for this time of the year, will look fresher for President Reagan's visit next month.
In one of the world's most polluted cities the campaign has also become a focus for China's environmental reforms. Early this year the government announced that new industrial projects without adequate antipollution measures would be banned and low-profit factories that were creating serious pollution problems would be closed down.
At a recent conference on environmental protection, Vice-Premier Li Peng said that moves to control pollution had been mapped out for the next seven years as a principal consideration of China's modernization program. Mr. Li also recommended that central departments and local governments set aside money each year for antipollution measures.
''It is absolutely wrong to think that pollution is an inevitable part of modernizing a country,'' Mr. Li said.
Civic virtues month has also incorporated China's tree-planting day, March 12 , which is the zenith of China's attempts to remedy the deforestation that took place across the country early this century.
This year every Chinese citizen is expected to plant five trees - up from three in past years.
Oddly enough, the month-long campaign also involves the blasting of music from speakers atop most of Peking's tall buildings. Presumably it is to brighten the atmosphere, but the offical press has yet to explain the benefits or lessons to be learned from the unsung versions of ''Yes sir, I can boogie'' and ''Auld lang syne'' that floated through the streets of Peking last week.
But the need to make the clean-up campaign an annual event is a sign of its general lack of success. In the end it is like most regulations announced in China: widely covered in the offical press but given little attention by most of the populace.
In the words on one Chinese citizen who has gone through countless campaigns in his 60 years: ''Civic virtues month? Wait until the first of April and then do what you want.''