Insisting again that it will never negotiate with the Communist mainland, Taiwan today brushed aside recent unification feelers from Peking as merely a new gambit of subversion.

"We shall not negotiate with the Chinese Communists under any circumstances," said Vice Foreign Minister Fredick Chien.

In a news conference with foreign reporters, Chien also said his government has not altered its opposition to the development of nuclear weapons and said the construction of long-range missiles is purely for defensive purposes.

Chien's responses to questions revealed no shift in the nationalist government's long-standing opposition to talks with Peking, despite the flurry of hints and rumors from the mainland since the sudden announcement last week of normalization of relations with the United States.

Observers have noted conciliatory remarks from several chinese leaders, See Taiwan, a18, Col. 1 Taiwan, From a 17 including Chairman Hua Kuo-feng. In his news conference last Saturday Hua avoided China's traditional threat about "liberating" Taiwan and said he hoped "our compatriots" in that island country would join other oversea Chinese people "in making further contributions to the cause of reunifying China."

In another widely reported development, a member of the Communists' National People's Congress, Chen Yi-sung, predicted that negotiations between Peking and Taipei would start soon and the reunification could come in 1979. He said, however, that he was speaking for himself and not for the Chinese Government.

Chien today described such reports as typical of negotiating tricks employed by the Communists since 1921. They have used "intermittent" tactics of both peace talkd and warfare to defeat nationalist forces and are now trying the soft approach, he said. "This is how we lost the China mainland-we will not commit the same mistakes we made in the 1920s and 1930s," the diplomat declared.

He claimed offers of negotiations represented a feeling of "weakness" on the Communist mainland where the government now realizes it plans to modernize the country's industry and agrculture ard failing. It is also, he said, a new attempt at "subversion" designed to undermine the morale of the Taiwanese people.

He said the "great majority" of them support their governments decision not to negotiate on reunification. In response to a question, he said there are no current plans to hold a referendum on the issue.

On Jan 1, the United States will formally establish relations with Peking and withdraw recognition of Taiwan but no details of the changeover have been disclosed, and officials said a timetable is yet to be established.

It appeared that Taiwan may actually make the first move, Chien said today that Taipei's ambassador to Washington will come home before the Jan 1 deadline , although other personnel will remain there for a period of time.

Although the United States is abrogating the mutual security treaty with Taiwan, some 60 other cultural and trade agreements will apparently be honored on both sides, although many of them must be legislated in new form after diplomatic relations are severed.

Chien began meetings Tuesday with the U.S. ambassador here, Leonard Unger, and the first priority was given to the future of Taiwanese living in the United States.

Chien said he asked for assurances that those persons travelling on Taiwan passports would be "adequately protected" in the United States and would "not be molested by Communist agents after Jan 1." He said he received satisfactory replies from Unger.

He said that he and Unger also have begun discussing the establishment here of some organization to represent U.S. interests when the embassy is closed, but declined to reveal any details. Like many other governments, the United States is expected to operate a quasiofficial representatonal office here that will perform many duties of a regular embassy. U.S. officials said today the makeup and role of the organization has not been determined yet.

The vice foreign minister also denied categorically suggestions that his government has decided to development nuclear weapons when the American defense commitment is lifted. He noted that his country was an original signer of the cuclear nonprolicferation atreaty and said there is no plan to abandon that position.

Long-range missiles being developed here are solely for defensive purposes, he said. Several government legislators have suggested the development of nuclear arms but there has been "no agreement" to take duch a step, he added.

He also made it clear the government expects the United States to continued selling miliatary equipment to Taiwan indefinitely. The United States has retained the right to continue supplying arms to Taiwan and will fulfill orders of some $140 million in the current year.

"The United States is committed to supplying us with defensive weapons," Chien said. Beyond the current year, Taiwan has not received "definite assurances" of further sales but has been promised that its future requests will be considered, he added.