Li Xiannian, a veteran Communist leader who straddles China's political factions, was named today as the nation's first head of state since the 1960s.

Li, 73, an orthodox Marxist economic planner who has survived every sharp turn in Chinese politics for more than 50 years, is regarded as a compromise choice, acceptable at once to Communist Party reformers led by Deng Xiaoping, the political old guard and military conservatives.

The state's nominal parliament, the National People's Congress, went through the formality of electing Li president by secret ballot, but he reportedly was tapped for the job months ago by party elders who controlled the nominations.

Deng, 79, China's paramount leader who turned down the presidency as too taxing, was elected chairman of the state's central military commission, matching his role as chief of the party's more powerful military board.

Two prominent Deng supporters on the party's Politburo--Ulanhu, 77, a minorities specialist of Mongolian descent, and Peng Zhen, 81, former mayor of Peking--were elected state vice president and chairman of the parliament, respectively.

The office of state president was restored last year theoretically as protection against the kind of arbitrary, one-man rule fashioned by the late party chairman Mao Tse-tung, who inspired the destructive Cultural Revolution.

Mao had the post abolished in 1975, nine years after China's last president, Liu Shao-chi, was toppled by Red Guards. Liu died in prison in 1969.

Although the presidency is supposed to diversify sources of power, the post is largely ceremonial and is regarded by foreign analysts as a government front for the party hierarchy that really runs the nation.

For Li, a crusty revolutionary war commander, the new office is less influential than his membership on the Politburo's six-man standing committee.

In his party role, he is a forceful proponent of orthodox economic measures now in disfavor under Deng's leadership.

But Li is believed to have been pivotal in formulating China's new strategic independence. He was publicly critical of the United States before other Chinese leaders, branding it imperialist as far back as January 1982. He also was the first publicly to endorse normalization talks with the Soviet Union, 10 months before they began.

The presidency may provide Li a new platform for his views, but it carries none of the institutional levers to strenghten his hand in the Politburo, where Deng's reform faction sets the nation's agenda.

Li represents the old guard faction of party and military officials who survived the Cultural Revolution unscathed and who oppose many of Deng's reforms, including wholesale disavowal of Maoism, restructuring of the economy, low defense budgets and efforts to retire aged cadres.

Li, who joined the party in 1927 and participated in its historic "Long March" retreat to the Yenan guerrilla base, was initially attacked during the Cultural Revolution as a "capitalist roader." But he was protected by then-premier Chou En-lai and, unlike Deng and his team, remained in power during the chaotic decade from 1966 to 1976.

Although Li has forced certain compromises on the reformers since they seized control in 1978, Deng is believed to view him as a member of the loyal opposition and an occasional ally who has helped oust Cultural Revolution radicals from the party leadership.

"Giving Li the presidency is a concession by Deng, but a concession that isn't going to cost him much," observed a western diplomat.

At the same time, Li's ascendency is expected to hearten other old-line forces who fear Deng's reforms as a strategy for sidelining any official who lasted through the radical decade without trouble.

As an advocate of fast economic growth spurred by heavy industry and financed by oil exports, Li also is popular with China's military-industrial complex, known as the "petroleum faction."

Its members in economic ministries, industrial plants and the Army believe Deng's go-slow, consumer-oriented program retards development and imperils jobs, including their own.

Li, a former finance and trade minister who became a Politburo member in 1956 and stayed at or near China's economic helm for 25 years, withdrew from daily economic affairs after delivering a "self-criticism" at a party work conference in December 1980.

He admitted erring in a grandiose development scheme unveiled in 1978 that resulted in massive budgetary deficits, inflation and unfinished capital construction projects. On the financial sidelines, however, Li has continued to cheer on the "petroleum faction."

Since giving up the economic reins in 1980, Li is said to have focused his attention on foreign policy, heading a small Politburo committee in charge of diplomatic and strategic affairs.

Although little is known of his private role in shaping foreign policy, Li was an early and forceful spokesman for China's strategic independence. After a pro-U.S. tilt from 1978 to late 1981, Peking has gradually moved into an equidistant posture between the two superpowers.