China has begun to restrict severely the number of parcels coming in from Hong Kong and Macao, a significant sign of Peking's discomfort at the tons of food and clothing its citizens have been receiving from relatives here.

The China Postal Administration informed the Hong Kong Post Office that as of Sept. 1, no household in China could receive more than four parcels a year, with no parcel value at more than $11. Previously, Peking allowed each individual to receive one parcel a month.

The Chinese have also put new restrictions on parcel contents. Medicine is no longer allowed to be sent into the country without the written permission of a mainland Chinese doctor. Clothing and linen must be brand new. Food may weigh no more than 11 pounds.

U.S. State Department officials said that as far as they know, the new rules apply onlty to packages sent from Hong Kong, not from the United States.

The new parcel restrictions appear to be designed to encourage Hong Kong residents to send their Chinese relatives money instead of goods, thus providing hard currency that China needs badly for its foreign trade. Peking has imposed no prohibitions or limitations on the amount of money mainland Chinese can receive.

The Chinese are also undoubtedly interested in curbing the occasional strife that breaks out in small Chinese communities when a few villagers receive luxury items like clothing or vegetable oil in the mail.

Some Hong Kong residents are not happy about the new rules.

"Money is useless to my cousin. In the village where he lives, there is nothing he can buy," said one woman. "What he and his family need most is cooking oil. But now with the quantitative restriction imposed on foodstuffs, it will be difficult to send him even that."

To many here, however, the obligation to supply mainland relatives has been a nuisance, and they welcome an excuse to cut back.

"They think we own a gold hill here, writing us all the time asking for this and that," said one man, "Now we don't have to give them any other explanation for not sending stuff to them more frequently."

The number of parcels sent into China has almost doubled since parcel service between China and Hong Kong resumed at the end of 1971. A majority of this city's 4 million residents have close relatives in China. According to Hong Kong Post Office figures, 773,900 parcels were sent to China in 1975-1976 as compared to 483,600 parcels in 1971-1972.