Government officials yesterday put the final touches on a directive to the Commissioner of Customs that will slap a quota on five categories of Chinese textile exports to the United States.

A letter from Assistant Commerce Secretary Robert Shepherd, as chairman of an inter-agency textile committee, is expected to be signed on Monday, and published in the Federal Register on Wednesday.

The quotas will be effective for the period May 31, 1979, through May 30, 1980. Officials explained that while an actual customs tally connot begin until publication of the directive in the Federal Register, any shipments from May 31 through the publication date will later be counted against quota limits.

Thursday was the date on which Special Trade Representative Robert S. Strauss, failing to reach a bilateral agreement with representatives of the Peoples Republic in Peking, notified Foreign Trade Minister Li Qiang in a formal letter of the U.S. intention to apply unilateral textile quotas.

The quotas will be on cotton gloves, 2.946,006 dozen pairs; cotton blouses, 535,569 dozen; cotton shirts, non-knit, 354,613 dozen; and man-made fiber sweaters, 334,834 dozen.

The significance of the May 31 date is that it throws the Chinese quota back to a base year ending March 1979. The base is calculated on the first 12 of the prior 14 months. Peking had been boosting its exports in recent months in anticipation of import limits, hoping that the heavy sales in the past couple of months would be counted in the base.

Strauss' letter to Minister Li indicated that China had had precise forewarning of the exact quota limits the United States would apply, as a way of averting "market disruption." Without quotas, the U.S. feared that markets here would be flooded with Chinese textiles.

The letter reflected a friendly tone, and assured China on behald of President Carter that the United States would do all possible to resolve differences on the textle problem. Strauss assured Minister Li that the United States was prepared to continue negotiations for a bilateral deal at the earliest possible moment.