Peking said yesterday that its relations with Hanoi were "deteriorating" as the number of refugees from Vietnam climbed to nearly 90,000 and plans were revealed to evacuate residents of southern Vietnam's huge Chinese community.

In its first lengthy statement on the widening split between the two Communist neighbors, the Vietnamese Foreign Ministry called for "negotiated settlement" but dismissed as 'sheer fabrications" Peking's vehement charges that ethnic Chinese are being persecuted in Vietnam.

Peking said on Saturday that it planned to evacuate all remaining "persecuted Chinese" from Vietnam. U.S. analysts have estimated that there are about 2 million ethnic Chinese in Vietnam.

Peking continued its newspaper, radio and television barrage against Hanoi yesterday in what seemed a deliberate attempt to incite anti-Vietnamese feeling among 800 million Chinese. The official New China News Agency reported 17,000 "victimized Chinese" had crossed the border from Vietnam between May 21 and 26, bringing the total to 89,700 since last year with most of those reaching China in the last two months.

The news agency said it had learned from the government's Overseas Chinese Affairs office "that Vietnamese authorities are continuing their persecution and explusion of Chinese residents, and the situation is deterioration."

Following its announcement Saturday of plans for a mass evacuation, Peking revealed in a note to the Vietnamese Foreign Ministry that it wished to send ships not only to Haiphong in northern Vietnam where most refugees so far appear to have originated, but also to Ho Chi Minh City (formerly Saigon) in the south. It is estimated to have as many as a million ethnic Chinese residents.

Peking charged last week that some ethnic Chinese in the city had been killed or wounded in recent distubances. Chinese news reports yesterday began to focus on the plight of some refugees who had managed to travel all the way from Ho Chi Minh City to China on their own, but were now worried about relatives left behind.

The Vietnamese reacted to the prospect of a mass exodus of Chinese from their largest southern city by calling a meeting of Ho Chi Minh City leaders. The group, meeting on Saturday expressed "great indignation" at the "slanderous charges" concerning treatment of Chinese "in Vietnam in general and in Ho Chi Minh City in particular," according to a report yesterday by the official Vietnam News Agency.

In its statement, the Vietnamese Foreign Ministry blamed the sudden rush of Chinese out of the country on rumors spread when fighting between Vietnam and Cambodia broke out late last year.

Cambodia has been heavily supported with weapons and supplies by Peking while the Soviet Union has remained Vietnam's major ally. The ministry quoted what it called "information spread among" Chinese in Vietnam that "China supports Cambodia against Vietnam, war will break out between China and Vietnam, Hoa (Chinese) people in Vietnam will suffer losses. They must therefore find ways to leave Vietnam quickly."

Many of the disturbances in Ho Chi Minh City have been attributed to Chinese shopkeepers protesting Vietnamese efforts to end private business.

The ministry statement said "a few" had "tried by every means to elude . . . socialist transformation of private capitalist commerce." The ministry also complained that although Chinese in Vietnam had been welcome in all kinds of jobs and professions, "Vietnamese residents in China enjoy only very limited rights."

In calling for a "negotiated settlement," the ministry said, "The Vietnamese side proposes that propaganda aimed at playing upon people's feelings, harmful to the friendship between the two people's, be stopped, and that representatives of the two governments meet to settle the differences . . ."

The official Vietnam News Agency reported that Vice Foreign Minister Hoang Bich Son received a note delivered by Chinese Ambassador Chen Chi-feng Saturday. After reading the note, the agency said, the Vietnamese official pronounced Chinese charges of persecution as "sheer fabrication." "Concerning the Chinese side's proposal for sending ships ot Haiphong and Saigon ports, Vice Minister Hoang Bich Son said he will report it to higher quarters," the news agency said.

Peking has a fleet of about 365 merchant ships, some of which may already be in Vietnamese harbors aspart of the regular trade between the two countries. The ships could be used for transporting refugees, although it remains unclear when they would be authorized to take on refugee passengers and how many Chinese remaining in Vietnam would wish to leave.

The New China News Agency sent articles yesterday hailing Saturday's ate refugees by sea. "Returned Chiate refugees by sea. "Returned Chinese Liu Jui-hsia was lying in bed, shedding tears for missing her dear ones," the agency reported

"On hearing the news, she jumped out of bed and said, 'I have my mother, brothers and sisters still in Ho Chi Minh City. It's really good news that our government sends ships to bring them home."

Another man newly arrived in the border region of Kwangsi with his 4-year-old son said his wife remained in Ho Chi Minh city "too weak and ill to stand the long journey." A blind woman who said she was beaten and robbed by Vietnamese police on her way to China also hailed the plan to send ships, the Chinese agency said.

There was no official Chinese response to Hanoi's requestr for negotiations. Peking has also not responded so far to reports from diplomats here and from the East German news agency that it has stopped all Chinese aid projects in Vietnam in retaliation for Hanoi's actions. The last diplomatic reports reaching here from Hanoi said there was no sign of activity on those projects which foreigners could observe.