China has agreed to join with an American firm in building a 19-story luxury hotel in Peking, scheduled to be the largest hotel in the Chinese capital and the first Sino-American joint venture under new investment guidelines.

Chinese authorities took the unusual step of announcing on the front page of the Communist Party newspaper, the People's Daily, their approval of the $70 million to $80 million "Great Wall" hotel. The plans include a swimming pool and a computerized accounting system, unheard of at hotels here. Construction is expected to begin this year, and the hotel is scheduled to open in 1983. The prominent announcement of the landmark deal indicated Chinese interest in encouraging further such ventures despite delays in negotiations involving several other American companies here. It also underlined the advantages to American companies who have Chinese-Americans actively involved in the negotiations, in this case former Bendix Corp. Vice President C. B. Sung of San Francisco.

China's newly created Foreign Investment Commission ratified the contract between the China International Travel Service and the E-S Pacific Development and Construction Co. Ltd., whose principal officers are Sung and financier Cyrus Eaton Jr. The firm last year underscored its interest in the Chinese market with a $150 million investment in the government's new Chinese International Trust and Investment Corp.

The foreign investment commission also announced approval of two other joint ventures for construction of a smaller hotel in Peking with a Hong Kong company and for a new catering service at Peking's new international airport, also with a Hong-Kong firm.

Sung, reached at his home in San Francisco, said under the new Chinese guidelines the government travel service will hold 51 percent and his company 49 percent interest in the hotel and split profits accordingly.

The success of the recently organized American firm's venture here contrasts sharply with the difficulties encountered by International Hotels Corp. in pursuing a preliminary agreement signed in November 1978 to build five or six hotels.

No final agreement has been signed for the deal, once estimated at $500 million. A spokesman for Pan American World Airways, which owns International Hotel Corp. said talks still are "progressing slowly."

In early 1979 China seemed to step back from many large preliminary development deals with western companies. Peking underwent a major reassessment of its economic resources, and since then has moved forward cautiously, committing itself mostly to smaller projects on a step-by-step basis.

The Chinese have continued to view tourism, however, as a relatively easy way to rapidly increase their foreign exchange earnings. Significantly. The three joint ventures announced today -- the American-backed 1,000-room "Great Wall" hotel, the Hong Kong-backed 528-room Jianguo Hotel and the catering service -- all are designed to increase tourist services. Peking received 150,000 tourists in 1979, up 41 percent from 1978, but the facilities here were strained severely.

Asked about his success in winning final approval for a contract before Intercontinetal Corp., Sung suggested the worldwide publicity given the larger firm's preliminary agreement may have made the Chinese more reluctant to proceed.

Sung said his company has arranged for Becket International to help design and manage construction of the "Great Wall" hotel jointly with the Chinese. The building is to be erected on a site halfway between the center of Peking and the Airport, nowhere near the Great Wall of China. The joint management of the hotel will be handled by personnel provided by Eaton, who already is experienced in managing hotels in Socialist countries such as Yugoslavia and Romania.

A Chinese official here, reading of the hotel deal, suggested a hotel be built next to the Great Wall. When a foreigner expressed doubts that this could be done, given the steep terrain, the Chinese said "but we built the Great Wall, didn't we."