The South Korean government today restored the civil rights of opposition leader Kim Dae Jung, clearing the way for him to run for president if elections are held next year.

Kim, who had spent years in prison and under house arrest, was granted a special amnesty along with 686 other South Koreans who once had been arrested for violating decrees imposed by the late president Park Chung Hee.

More than half of those amnestied were students. But many politicians, journalists and religious leaders also benefited from President Choi Kyu Hah's decision to restore civil rights on a broad scale.

Among them were a former South Korean president, Yung Po Sun, and a Quaker dissident leader, Ham Sok Hon.

The amnesty was announced this morning in Seoul by President Choi's press office. Choi said he acted "to provide the basis for national reconciliation and enable the people to join equally in the ranks for national development."

There was no indication how the martial law government viewed Choi's mass reinstatement of civil rights. The military has wielded considerable power since Park's assassination last year. Former martial law commander Chung Sung Hwa had told South Korean editors at one point that Kim Dae Jung should not be permitted to run for president. Chung was overthrown in a military coup by a group of generals who have given conflicting signals of their attitude toward politicians.

The restoration of civil rights, besides returning Kim Dae Jung to the political arena, also means that others can now seek jobs from which they were once barred.

The announcement removed one of the major barriers between Choi's government and former dissenters and was sent as another step in fulfilling the new government's promises to rid the country of the vestiges of Park's strongman rule.

The government, which took office after Park was assassinated last October, already had freed many political prisoners arrested under his administration and discarded the emergency decrees under which Park's police were able to arrest anyone who criticized the government.

Hundreds were arrested during the last seven years of Park's rule for demonstrating in the streets, publishing antigovernment remarks or signing statements criticizing the government's harsh behavior toward dissidents.

Several dissenters who were also convicted of violating the government's anticommunist law remain in prison. Among them is Kim Chi Hah, a poet.

At a news conference in his home in Seoul, Kim Dae Jung charged that the government's amnesty was long overdue and failed to include some he said deserved amnesty, according to Japan's Kyodo News Service. He said all other political prisoners should be freed.

Choi, who has promised to be a short-term caretaker president, was elected in December to the dismay of Kim Dae Juns and other dissidents who had wanted the election delayed until a new and more democratic constitution is in place.

Under a schedule tentatively outlined by the present government, a new constitution will be devised and enacted late this year, and the first presidential elections would be held in 1981.

Kim Dae Jung is likely to be a prominent candidate. In an interview last December shortly after being released from house arrest, he said he looked forward to being a candidate and believed his chances would be good if the new constitution is democratic and if the elections are fair.

"If we have those, I believe I have a good chance," he said then. "If not, it is hoepless."

Kim Dae Jung ran a close race against Park in 1971, winning about 45 percent of the vote. In 1976, he was sentenced to a five-year term in prison for violating one of the antidissent decrees. Park freed him after 33 months in jail, but he spent much of the time since then under house arrest because of his frequent antigovernment declamations.

If he runs for president, Kim may cause some friction within his own New Democratic Party. The party's current leader, Kim Young Sam, is one of his champions, but has already indicated he would seek the presidency and has made a number of what appear to be preliminary campaign appearances.

The contest could therefore pit old friends against each other. Kim Young Sam won the party presidency last May in a closely contested election when he gained the last-minute support of Kim Dae Jung.

Kim Young Sam paid a visit to congratulate Kim Dae Jung on his amnesty today.

The third likely candidate in the race is Kim Jong Pil, a leader of the party that was once the personal machine of President Park.