In July, 1974, Chang Sungnam, then the editor of a newspaper in Washington that opposes the South Korean government, asked for political asylum in the United States.

He had written editorials critizing the dictorial of South Korean President Park Chung Hoe. He became chairman of an anti-government "human rights" group. He said his brother-in-law in Seoul had been imprisoned and his family here threatened by the South Korean Central Intelligence Agency.

Early this month, after three years of bureaucratic delay, Chang finally got his answer - no. He received two form letters. The first said he had failed to establish a case that he would be persecuted if he returned to his homeland. The second, a few days later, said he had two weeks to leave the country before deportation proceeding began.

Chang was in a position to respond to the derective he had just undergone a second operation to ease the pain of an inoperable, baseballsize cancer growth in his growth in his stomach.

A after inquiries from The Washington Post, the Immigration and Naturalization Service sent Chang another letter, this one delaying his departure for one year.

But the reprieve does not explain why the case took three years. Nor does it affect the legal limbo facing the 40-year-old Chang and his family, who do not qualify for government assistance in paying hospital bills that total more than $30,000.

Indeed, a review of the Chang asylum request raises questions about the way the State department and INS handle the sensitive diplomatic issue of persons who seek safety from governments friendly to the United States.

James L. Carlin, an official at the refugee and migration affairs section of the State Department, insisted in a recent telephone interview that the department does not have a policy of rejecting asylum requests from citizens of allied governments such as South Korea.

"We deal with these cases on an individual basis, whether or not we've got a special relationship with the government in question," he said.

President Carter has said publicly that his administration was concerned about human rights violations in South Korea, a longtime ally of the United States.

But the most recent INS statistics show that no South Koreans are among the more than 2,000 persons now in the United States in asylum staus.

One State Department official said this was because it is "relatively rare" for South Koreans to apply for asylum. Others charge it is because granting such refuge would be a slap in the face to a friendly regime.

Donald L. Ranard, head of the department's Korean desk in the early 1970s, said, "There's always been a general feeling that we'd like to handle that kind of case out of the limelight."

Lee Jai Hyon, a South Korean diplomat who asked for asylum in 1973, said he was allowed to stay in the United States after an "adjustment of status. They didn't want to call it asylum," he said.

Boh Lee and Ranard said they were sure Chang would be jailed because of his anti-government activities if he ever returned to South Korea.

In a recent study of U.S. political asylum policies for the Carnegie Endowment for International Peace, Christopher Hanson found that persons fleeing Communist countries are almost automatically granted asylum. Those seeking refuge from right-wing dictatroships, on the other hand, are seldom able to win their cases, he said.

Carlin of the State Department said he did not have figures on how many South Koreans had applied for asylum in recent years. But he said he was surprised that INS had rejected Chang's application because he personally had written immigration officials last month to say, "We believe it is appropriate to err on his side and recommend that Mr. Chang not be forcibly returned to Korea at this time."

"I've never known them to go against our recommendation," Carlin added. "I fear they misunderstood our letter."

The letter did not, however, recommended that Chang be granted asylum. And it came 27 months after INS had first asked the State Department for an opinion in the case.

After Chang applied for asylum in mid-1974 he was interviewed three times by immigration authorities, a review of his file shows. In April, 1975, and again a year later, INS wrote to State asking that Chang's documentation be reviewed and an opinion be offered.

It wasn't until November, 1976, that the State Department first replied. And though that response concluded that "Mr. Change probably does have valid reason to ask not to be forcibly returned to his home country," it asked that he provide more support for his claim.

Immigration wrote again last December, noting that it had begun to get inquiries "from community leaders" about the case. Finally last month, Carlin's formal recommendation was made.

In the letter, Carlin said the State Department couldn't confirm Chang's claim that his brother-in-law had been jailed, but that it had some doubts about the case.

INS didn't accept State's recommendation, though, and the form letters announcing the denial and the order to depart were sent out.

Joseph A. Mongiello, the INS district director, said there "may have been other information" besides the department's opinion that figured in the rejection of Chang's asylum request.

The decision has left Chang's wife, Jin-ok, disillusioned about the United States. She said it should have been easy for the State Department to check on the arrest of her brother in Seoul. "That letter was just an excuse," she said. "We didn't ask much. Just that this country protect us and let us work.

"When my husband got sick I though they could help me humanly. I begged them to give us a chance. I thought it would be different under President Carter because of all he's said about human rights."

Now friends in the Korean community are trying to raise funds to pay the soaring hospital bills and provide for Chang's wife and child.