South Korea's new president today abolished the emergency decree that had been used by slain president Park Chung Hee to jail hundreds of his critics.

Lifting the emergency decree was President Choi Kyu Hah's boldest move so far in his effort to appease dissenters and to obtain their support for his interim government.

Choi's government released 68 prisoners, among the last to be jailed under Park's rule. A larger number had been expected but officials said 46 were freed earlier.

It also appeared to open the door, literally, for freedom for the most celebrated opposition leader, Kim Dae Jung. He has been under house arrest for months for violating terms of a parole from his conviction under the emergency decree. Sources in Seoul said Kim would be free to move around and receive visitors Saturday or Monday.

In a statement, Choi, who was chosen president yesterday by the electoral college, appealed to the prisoners to be released to join in a campaign for national reconstruction.

"I earnestly ask the prisoners to be released to take part in the government's constructive effort for national development considering the reality that we are facing at home and abroad," Choi said.

The emergency decree, which Park had issued in May 1975, was the most controversial element of his rule because it gave him sweeping power to arrest without warrant anyone who criticized the government or the constitution.

Hundreds of Christian ministers, students, journalists, professors and even national legislators were imprisoned during the 4 1/2 years of the decree's life. Reporters were jailed for critizing censorship and could be arrested for reporting the arrests of others under the decree.

Most of them had been set free in the periodic amnesties ordered by Park. More than a hundred came out of prison under a reprieve issued by the late president shortly after the state visit by President Carter last summer.

The emergency decree had been one of the sorest points of contention between South Korea and the United States, particularly after the Carter administration took office with a special commitment to protect human rights.

The decree also became the central point of controversy between Park's supporters and the political opposition after the president was assassinated Oct. 26.

The opposition New Democratic Party insisted in negotiations with the progovernment party that no policy of healing the country would work until Park's decree was abandoned.

Both parties finally agreed last week to approve a resolution calling for its repeal. Once the resolution was passed, it was assumed that Choi would go along.

Choi was elected by the same National Conference of Unification, a kind of electoral college, that had elected Park last year. There was no other candidate. The opposition party had insisted that the conference -- also part of Park's "Yushin constitution" -- be abolished and that Park's successor be elected directly by the people.

But while the emergency was being done away with, military authorities who supervise law and order were arresting dissenters under their own proclamations, which have been in effect since martial law was declared the day after Park's murder.

Scores of Christian activists, students and other dissenters have been arrested for joining in criticism both of martial law and the interim government headed by Choi. Many are still being held and the martial law command has repeatedly served notice that it will not countenance street protests or criticism of the state.

In another development, the entire Cabinet left over from Park's government submitted resignations during an hour-long Cabinet meeting presided by Choi. He is expected to accept most of the resignations next week and name replacements.

Choi has indicated that he will not serve out the entire five years remaining in Park's term but will resign once a new constitution is approved and in force. But he has not said definitely when he will step down to permit the election of a successor.

A career bureaucrat who was prime minister under Park, Choi was the choice of most government party members and Cabinet officials as caretaker president. He also has the tacit support of military leaders who have wielded great power in civilian affairs since Park was assassinated.