Chang Sungnam, a South Korean newspaper editor who asked for political asylum in the United States because of his anti-Korean government views, died yesterday in Arlington Hospital after a long illness. He was 40.

Mr. Chang came to the United States in 1969 to do graduate work first at Emory University in Atlanta and then at Howard University in Washington. In 1973, he started a Korean-language newspaper here, called The Free Republic, which was critical of the regime of South Korean President Park Chung Hee.

In 1974, Mr. Chang applied for political asylum in the United States, but heard nothing from the Immigration and Naturalization Service for three years. Then in August, while he was hospitalized with inoperable stomach cancer, he received a form letter from INS saying his asylum application had been denied and that he had two weeks to leave the country.

After inquires from a reporter, INS sent Mr. Chang another form letter, delaying his departure for a year.

A story about his request for asylum was followed by several letters of protest to INS about the handling of his case, but resulted in no change in his status.

Mr. Chang was chairman of the Congress of Civil Liberties in Korea, organization in this country. He is suvived by his wife, Jin Ok, and a son Key Young, of the home in Arlington.