The Reagan administration was cautiously optimistic yesterday about the new trade liberalization measures announced by the Japanese government, although Sen. John Danforth (R-Mo.), leader of the trade reciprocity movement on Capitol Hill, said he will proceed with his reciprocity legislation anyway.

"While this package does not solve all our problems, it goes a long way toward recognizing them and in committing the Japanese government to take part of the steps for their solution," said Commerce Secretary Malcolm Baldrige.

U.S. Trade Representative William E. Brock said the new trade package was "the result of an exceptional effort and demonstration of political will."

Brock said many of the Reagan administration's concerns seem to have been addressed in the announcement, but added that "these measures do not, of course, address all of our difficulties."

Treasury Secretary Donald Regan joined in cautious praise of Japan's steps, but said "the failure to reduce some tariffs of special interest to the United States is disappointing." Regan didn't say what those tariffs were.

The reduction or elimination of 215 import tariffs was the second such measure taken this year by the Japanese government following complaints and negotiations between Washington and Tokyo on barriers to sales of U.S. goods in Japan.

The announcement, not coincidentally, was made one week before the Versailles economic summit at which Japan was expected to be a scapegoat for the depressed economies of America and Europe. Last year Japan's trade surplus with the United States was $18 billion, and it is expected to go as high as $25 billion this year.

"The timing of the Versailles meeting was very much in our minds in making the announcement" of the trade package, said Yoshio Okawara, Japanese ambassador to the United States, during a press conference. He also noted receiving "pressure from the U.S. and Europe."

Last January the Japanese government ordered the easing or elimination of 67 nontariff barriers, but U.S. officials and Congress criticized that measure as being repetitive and not going far enough.

Okawara said he expects the administration and Congress to accept the new package more positively than they viewed the last one. "We have bitter memory of the 67 steps announced in January , and I think we should be much wiser now," he told reporters.

Danforth said that, although the measures "are limited in scope and their impact is uncertain, the market-opening measures clearly show that Japan is moving in the right direction." Danforth said his bill to provide reciprocal treatment in trade should be taken as part "of the continuing process to open Japan's market."

Noticeably absent from the package was liberalization of barriers to U.S. beef and citrus products and high-technology goods, major negotiating points of the Reagan administration and Capitol Hill. However, Okawara said talks will be held this fall on that issue.

However, Baldrige noted improvements in tariff reductions on computers, auto parts, medical equipment and photographic film. He also praised the establishment of a bilateral work group on high-technology industries and the promise that customs procedures would be improved.