For the first time in more than a year, South Koreans are able to read uncensored news reports about their country in foreign newspapers and periodicals.

Two American newsmagazines, Time and Newsweek, and the Hong Kong-based Far Eastern Economic Review, appeared on newsstands here this week with extensive stories on South Korea, none of which had been touched by the censor's scissors.

It was the first time since October 1979, when President Park Chung Hee was assassinated, that foreign journals appeared for sale uncensored.

Other reports of liberalization measures are described by knowledgeable sources as reflecting President Chan Doo Hwan's feeling that a largely successful state visit to Washington has made him popular enough to move away from hard-line supporters in the military.

Lifting censorship of foreign publications was the first step, they said. "Everybody agreed that there had been a lot of silly stuff [in the censorship] anyway," one source said.

After Park's death, military leaders taking over the government assigned censors to clip out offending articles paragraph by paragraph. For months, through a military crackdown last May and a bloody insurrection in Kwangju, censors either snipped out items or banned entire issues.

Under Park's long rule, foreign journals also were censored, but not as rigorously.

A government spokesman acknowledged that there had been a change in policy this year, in keeping with Chun's assertion that censorship was a thing of the past.

The government has said that with the lifting of martial law last month there will be no more censorship of any kind. However, major Seoul newspapers have been instructed in considerable detail as to what they can print. A government agent has been assigned as "liaison" with each publication, and editors expect retaliation if they do not obey the guidelines.

In a sweeping reorganization of the news media last fall, Chun's government took control of all national television and radio broadcasting systems. What South Koreans hear now is what the government wants them to hear.

Meanwhile, government sources hinted this week that Chun, who was assured of a seven-year term as president by favorable balloting this week for an electoral college, is planning new moves to loosen restrictions.

The sources said he was expected to eliminate some restrictions on foreign travel for South Koreans, who have long chafed at rules preventing their leaving the country except for specific, government-approved reasons. A businessman, for example, cannot usually take his wife abroad on business trips. The rules were imposed partly to restrict movement of dissidents and partly to keep foreign exchange from leaving the country.

Chun also is expected to announce an amnesty for a number of political prisoners when he is inaugurated early next month. There was speculation that there would be a reduction in the life sentence for Kim Dae Jung, the opposition leader, although some sources cautioned not to expect it.

Kim was sentenced to death on sedition charges, but the sentence was commuted to life imprisonment last month.

Reports were also circulating in Seoul this week that Chun would substantially reorganize his Cabinet and bring in moderate and onetime opposition figures to broaden the base of his government, which now largely reflects choices of him and military colleagues.

As for the new freedom for publications, most of the stories left intact this week dealt with Chun's Washington visit and the promises of support he received from President Reagan.

However, a few uncomplimentary remarks survived in print, and one magazine explained the international uproar over Kim Dae Jung's death sentence. Newsweek also carried pictures of North Korean President Kim II-Sung and of schoolchildren singing his praises.