Alvin Childress, 78, the actor who played sweet-natured Amos on the landmark "Amos 'N' Andy" television comedy series in the early 1950s, died April 19 at St. Erne Sanitarium in suburban Inglewood, Calif. He had Parkinson's disease and diabetes.

"Amos 'N' Andy" had been a popular radio program for years before CBS brought it to television in 1951. White actors had played all the leading roles on the radio. They were replaced by black actors when the program moved to television.

The racially stereotypical situations depicted in the series drew protests from various groups and contributed to the television series' demise, despite good ratings, in 1953.

Mr. Childress did not agree with the protesting groups. "I didn't feel it harmed the Negro at all. Actually, the series had many episodes that showed the Negro with professions and businesses like attorneys, store owners and so on, which they never had in TV or movies before."

Mr. Childress and Spencer Williams were the actors chosen after an extensive search to play the title roles on television. The program's plot involved the antics of a group of three friends in Harlem -- Amos Jones, Andy Brown and George (The Kingfish) Stevens.

Action often centered on the activities of The Kingfish, a conniving character who headed a lodge called the Mystic Knights of the Sea and who usually was looking for a dubious scheme to pursue with the aid of his lodge brothers. He was played by Tim Moore.

Amos was the philosophical, sweet-natured owner and sole operator of the Fresh Air Taxi Co. That role was rarely at the center of action, but Amos usually served as narrator. Andy was the most gullible character in the series, and his actions often drew from Kingfish the flabbergasted response, "Holy mackerel, Andy!"

Two members of the TV cast ensemble also played their parts on radio -- Ernestine Wade, who portrayed Kingfish's shrewish wife, Sapphire Stevens, and Amanda (Mama) Randolph, who played her mother.

Other characters included attorney Algonquin Calhoun, played by Johnny Lee; Andy's girlfriend, Madame Queen, played by Lillian Randolph, and the slow-moving janitor, Lightnin', played by Horace Stewart.

Mr. Childress graduated from high school in Meridian, Miss., and earned a bachelor's degree in sociology at Rust College. He went to New York in 1931 and first appeared on Broadway in "Savage Rhythm." He later joined the Federal Theater when it was formed and worked as an instructor with the American Negro Theater.

After the cancellation of his series, he was a social worker for Los Angeles County. Returning later to acting, he played a projectionist in the 1975 film "The Day of the Locust" and appeared in "The Bingo Long Traveling All-Stars and Motor Kings" in 1976 and "The Main Event" in 1979.

Survivors include his wife, Sophie.