Secretary of State Alexander M. Haig Jr. met with Communist Party Vice Chairman Deng Xiaoping today and both men characterized the extensive U.S.-Chinese talks being held here as "very good."

Yesterday, before meeting the man considered the most powerful figure in the country, Haig conferred with other Chinese leaders under a heavy clock of secrecy on strategic on military matters in lengthy meetings here.

Spokesmen for the U.S. side, saying there was "a great deal to discuss," reported that some of the meetings took much longer than originally scheduled. But under arrangements agreed on with the Chinese, nothing of the substance of the meetings was disclosed.

The official New China News Agency said of Haig's two-hour meeting with Defense Minister and Politburo member Geng Biao, only that "they discussed defense matters." A U.S. briefing official said nothing more.

Sitting in on the session were several high-ranking Chinese military officials, including Zhang Zhun Zi, who was identified as vice chief of military intelligence. Among those across the table on the U.S. side, in addition to Haig, a retired four-star general, was retired Gen. Vernon Walters, former deputy chief of the CIA.

Walters and several military-oriented U.S. officials held a separate luncheon meeting with Chai Chen Wen, director of the foreign affairs bureau of the Chinese Ministry of Defense. No information on the topics of this meeting was released. U.S. officials said in advance that Haig and his party were prepared to discuss strategic and military cooperation in considerable detail.

Haig began the day with a second lengthy meeting with Chinese Foreign Minister Huang Hua, whom he also saw Sunday. Yesterday's meeting lasted 3 hours and 45 minutes.

A brief New China News Agency announcement said the meeting included "a deep-going discussion on bilateral relations," suggesting that such items as the touchy Taiwan issue were major features, but a U.S. spokesman said "the bulk" of the session dealt with international strategic questions.

U.S. officials would not say whether the Taiwan issue was disscused.

A U.S. official close to the talks conceded that differences had surfaced. But he said that compared to some earlier periods of Sino-American contention, it was "all hearts and flowers" from the Chinese side.

Besides Deng, Haig is scheduled to meet Premier Zhao Ziyang today.

In addition to the military and security-related meetings yesterday, Haig saw Vice Premier BO yibo, who is responsible for moderization and economic matters.