Chinese Communist Party Chairman Hua Guofeng, speaking at his second press conference in three years in power, said today that members of a political faction led by the widow of chairman Mao Tse-tung would be subject to the "due process of law" before "too long" but would not be executed.

It was the first public indication by a top Chinese leader that the secret investigation of the celebrated "Gang of Four" might soon be completed. Hua refrained from saying they would have a trial, although China's new legal codes call for public trials in criminal cases and there have been unofficial suggestions that the purged faction would get one.

A public trial of the gang, including three former members of the ruling Politburo besides Mao's widow Jiang Ping (Chiang Ching), would be a sensational and unprecedented event here. Many observers feel the chances of reopening old political wounds are too great for the government to risk such a show, particularly since the four defendants, who have not been heard from since their arrest three years ago yesterday, might use the occasion to lambast the current Chinese leadership.

Hua spoke in response to a question, "Are you going to put the Gang of Four on trial?"

Hua replied: "We have been stressing socialist legality and our laws in the field have been adopted by the National People's Congress. The Gang of Four did a very grave harm against the Chinese people and these crimes will have to be settled but they will of course be handled in the due process of law. As to when this will take place . . . I can say it won't be too long."

After his answer was translated, Hua added: "I can tell our journalist friends that while we will deal with the Gang of Four according to legal procedures, we will not deal with them in the way they maltreated our cadres, we will not sentence them to death. I can tell you that they are living quite well, they are alive and well."

Jiang and her three allies, Wang Hongwen, Zhang Qunqiao and Yao Wenyuan, reportedly were arrested by Hua's order the night of Oct. 6, 1976, a month after Mao's death.

The group apparently had led an effort to purge several veteran party members in the last months of Mao's life and were bent on continuing Mao's policy of rewarding people in schools, organizations and the party for their loyalty and political fervor rather than their technical competence.

In the three years since their arrest, one of their principal adversaries, Vice Chairman Deng Xiaoping, has returned to power seemingly as great or greater than Hua's and has begun to return China to a merit system in nearly all phases of life.

Chinese legal scholars when questioned closely early this year about the chance of a trial for the Gang of Four, carefully hedged their answers. They indicated that the four former Politburo members might be charged only with crimes dealing with party rules and might not need a full public trial.

Hua's press conference was called in preparation for his trip beginning a week from now to France, West Germany, Britain and Italy. His only other recorded press conference occurred last December when he announced full diplomatic relations with the United States. Only journalists from the four countries involved were invited to the press conference, but one of them made available a tape recording of the 50-minute meeting.

Hua has accepted an invitation to visit the United States next year.

Asked about the democracy movement that has brought an outpouring of critical wallposters and some public demonstrations and arrests in the last several months, Hua said, "China is a socialist democracy, that is to say, it is a very extensive democracy enabling the people of our country to be really masters of their own affairs.

"We have been working steadily to institutionalize our socialist democracy and perfect our legal system. But I want our friends to know that we are opposed to anarchism and using democracy for purposes prejudicial to the rights of other people."

He said democracy would not be permitted "to the extent as to create social disorder."

The statement appeared to throw cold water on speculation here that the government might release some of the 20 young critics of Communist Party policy who have been under detention since last spring.

During the press conference Hua also noted:

That he would not visit the Vatican or attempt to see the pope or any other Vatican official because the Vatican still maintains official relations with Taiwan.

That he thought China's relations with Britain over the question of the future of Hong Kong were good and that "a reasonable solution" to the future of the British-held territory on China's southern coast could be found "through consultations" which would "take notice of the interest of the investors there."