Peking announced last night that Communist party Chairman Hua Kuo-Feng had retained his post as premier, defying predictions that the job might go to Vice Chairman Teng Hsiao-ping and indicating continued disagreement within China's power structure.

Besides reaffirming Hua as head of government, the fifth National People's Congress appointed a dour, 75-year-old army marshal, Hsu Hsiang-chien, to be defense minister. Hsu, thought to be close to Teng, assumes the task of modernizing the Chinese army and inherits a position whose previous occupants became powerful challengers to the authority of the party chairman.

Hsu replaced as defense chief the frail, 80-year-old Yeh Chien-ying, the country's second-ranking leader. The congress elected Yeh chairman of its standing committee to succeed the late Chu The, who served in that post as China's ceremonial head of state.

The appointments announced on the last day of the week-long congress, which serves as China's parliament, did little to dispel the image of a government led by very old men pursuing the pragmatic policies of Teng, 74, and his patron, the late Premier Chou En-lai. Hsu won out over two somewhat younger men thought to have been leading candidates for the defense post, including Peking army commander Chen Hsi-lien who had once been a sharp critic of Teng.

Official New China News Agency accounts reaching here last night extolled the congress' work as a sign of the new leadership's stability.

"We have held a meeting of unity, a meeting of victory," Teng said in remarks closing the congress session. The actual decisions, however, revealed a central ruling group still at odds over personalities, if not policies, 18 months after the death of Chairman Mao Tse-Tung.

Knowledgeable Communist sources in Hong Kong and Peking, including some delegates to the congress, predicted as recently as January that Teng would take over Hua's role as head of government. They emphasized the need to ease the strain on Hua, who holds more top posts than any man in the history of the people's Republic, including Mao.

Instead, Peking's top leaders apparently failed to reach a consensus on a replacement for Hua as premier. Mao installed Hua as premier and number two in the party a few months before his death, making him the obvious choice as new party chairman.

The new Chinese leadership, however, seems to have found it difficult to make other hard personnel decisions when there is no longer anyone with enough personal prestige to dictate choices, as Mao once did.

This has left Hua with extraordinary official authority, at least on paper. Little more than two years ago he was a vice premier virtually unknown outside China. Today he heads the party, the government, and, as chairman of the party's military affairs commission, supposedly controls the army.

He seems to have supported Teng's efforts to overturn some of Mao's egalitarian policies and return to discipline in factories and the merit system in schools. Whether he has resisted giving up the premiership is unknown. What is known of his earlier career as a provincial leader suggests a talent for bending with political winds except on a very few key issues.

The issues that seem to divide the post-Mao leaders include the resentment of officials like Teng, who were purged during the Cultural Revolution, toward usually younger officials like Hua, 57, who were promoted during that period.

The uncertainties in the post-Mao leadership also appeared in the lists of the party Politburo released before and during the congress. These 23 men actually rule the country but have failed to work out a pecking order for themselves as previous politburos did. They continue to list their names in the Chinese equivalent of alphabetical order, except for the top five leaders who are Hua, Yeh, Teng, Vice Chairman Li Hsien-nien, an economic financial expert, and Vice Chairman Wang Tung-hsing, a former Mao bodyguard who oversees the secret police.

Just how much such indecision over personnel will interfere with what appears to be unamious support for crash program to modernize the economy remains to be seen.

The leadership apparently decided not to complicate its personnal problems by reviving the post of president, or chairman of the republic, a job that was abolished at Mao's behest in 1975. Despite foreign speculation that the congress would appoint Hua or Teng to the post, no mention was made of it in the long official list of congress election results.

Instead, the congress voted -- as always on instructions from the party Politburo -- to add eight new posts to the old list of 29 ministries and departments under the State Council.

Many of the new appointments bear the stamp of Teng. His great influence derives from his encyclopedic grasp of foreign and domestic issues and the friendships he has forged during three decades operating near the top of the party and government.

Appointed to head the ministry in charge of guided missiles is Sung Jen-Chiung, 74, who has been a friend of Teng's for 40-years. Both men were purged during the Cultural Revolution of the late 1960s. As recently as last August, Sung's supporters failed to get him restored to the party Central Committee. But Teng's political resurgence shortly before that committee met has now drawn several old friends back into the government.

The new organs under the State Council demonstrate the government's all-out commitment to economic development. They are: the State Economic Commission, headed by former Petroleum Minister Kang Shih-en, the State Scientific and Technological Commission, headed by Politburo member Fang Yi; the Nationalities Affiars Commission, the Civil Affairs Ministry, the Ministry of Textile Industry, the All-China Federation of Supply and Marketing Cooperatives and the Ministry of Chemical Industry, which was formerly combined with the Petroleum Ministry.

The People's Bank of China -- the state central bank -- was promoted to the main list of State Council ministries after being formerly listed as a special agency. Its new head is Li Pao-hua, who was party chief in Anhwel Province before being purged in the Cultural Revolution.

The Chinese underscored the modernization drive, and perhaps Teng's influence, with an outpouring of press reminiscences yesterday on the 80th anniversary of Chou En-lai's birth.

Chou, who died in January 1976, had promoted the modernization drive and had picked Teng as his successor before a Politburo group led by Mao's wife temporarily pushed Teng aside. Hua, also a Chou protege, was installed as premier in a compromise in April 1976.

The congress also approved new lyrics for China's national anthem, "The March of the Volunteers", whose lyricist committed suicide after coming under heavy criticism for political wrong-doings during the Cultural Revolution.

The old words were written to inspire Chinese fighting the Japanese in World War II. The new lyrics add Mao's name to the chorus and portray a country on the move, rather than one that must be prodded to action. For the first line of the original, "Stand up, all you who refuse to be slaves!" The new lyrics substitute: "March on, brave people of our nation."