China today issued what it called a "strong protest" against White House plans to continue selling jet fighters to Taiwan, warning that it "will never accept any unilateral" decision by Washington to arm the estranged island.

The Chinese Foreign Ministry, in reporting the protest, said that U.S. weapons sales to Taiwan raise "a major issue affecting China's sovereignty" that can be resolved only through negotiation.

U.S. Embassy officials here said the protest was delivered verbally by Chinese Foreign Ministry officials meeting with Assistant Secretary of State John Holdridge, who was sent here to explain the arms-sale decision.

Diplomatic analysts said the Chinese protest, while critical of Washington at a crucial time, reflects a willingness to continue talks with Holdridge, who spent his second day here today.

Holdridge is believed to be seeking Chinese toleration of continued F5E sales to Taiwan in return for Washington's agreement to forswear sales of more sophisticated military aircraft.

China publicly demands an immediate cutoff of all weapons sales to Taiwan, but Chinese officials privately have hinted that Peking would tolerate the current level of arms transfers if Washington sets a time and quantity limit.

The brief Foreign Ministry statement gave no indication that Chinese leaders were at all assuaged by the Reagan administration's rejection of Taiwan's request for a jet fighter more advanced than the F5E it has now.

Holdridge's visit has been in utmost secrecy. Neither the Chinese nor the American side would disclose his activities today. He was seen this afternoon entering a state guest house where he met Foreign Ministry officials Monday.

China opposes U.S. weapons sales to Taiwan on the ground that the island is a Chinese province despite its 32-year separation from the mainland. Any military sale, say the Chinese, is an interference in Chinese domestic affairs.

Peking's demands on Washington have escalated since October, when Chinese leaders stepped up their campaign to win back Taiwan through peaceful means--a strategy they say is obstructed by U.S. arms sales.

The Foreign Ministry statement today was the first formal Chinese response since the State Department confirmed reports of the two-pronged decision to continue sales of F5E planes but to refrain from sales of more advanced fighters.

"The U.S. government has announced its decision to sell airplanes to Taiwan at a time when bilateral talks are going on," said the statement. "The Chinese government hereby lodges a strong protest against this."