WASHINGTON — Life expectancy for most Americans remained at a record high and infant mortality reached an all-time low, according to federal figures announced Thursday, but health officials noted that the United States lags behind many other industrialized nations in both areas.

Moreover, the life span for black males has shown no improvement during the last half of the 1980s, and, in fact, declined between 1987 and 1988, largely as a result of homicide and the AIDS epidemic, they said.

"America's health is good overall, and we are making excellent progress in many areas," Health and Human Services Secretary Louis W. Sullivan said in releasing the results of the nation's annual health checkup. "But this report also makes it clear that we need to do better."

Average life expectancy at birth reached 71.3 years for men and 78.3 for women, according to figures for 1987 and preliminary data for 1988.

"After a period when average life expectancy leveled off in the 1960s, the past two decades have seen life expectancy increase by more than four years," Sullivan said at a press conference.

However, he added, overall life expectancy in many industrial countries exceeds that in the United States. For example, he said, Japan has the longest overall life expectancy of any industrialized country--75.5 years for men and 81.6 years for women.

For black American males, longevity dropped in 1988 to 65.1 years, after an unprecedented two-year decline between 1984 and 1986 to 65.2 years from 65.6 years and no change in 1986 and 1987, the report said.

Sullivan attributed the drop to lack of access to medical care, AIDS and the high homicide rate for young black males, which in 1987 was more than seven times the rate for white males. The homicide rate among black males increased from 79.2 per 100,000 in 1986 to 85.6 in 1987, Sullivan said.

AIDS ranked ninth among causes of death for black men, 11th for white men, 16th for black women and 24th for white women in 1987, Sullivan said.

Infant mortality reached "the lowest level ever," Sullivan said, with 10.1 deaths per 1,000 live births in 1987, and, according to preliminary data, 9.9 deaths per 1,000 live births in 1988.

However, Sullivan noted the infant mortality rate is twice that of Japan. The United States ranks 22nd among industrialized nations and other selected countries for preventing infant mortality, the report said.