A new analysis of 1980 U.S. Census Bureau statistics showed that Prince George's County's black population is better educated and wealthier than in the 1970s. But it also showed a dramatic growth in the percentage of low-income households headed by black women.

Prince George's has the largest black population by percentage of any U.S. suburban county, the county planning department report noted, with the number of black residents exceeded only by Los Angeles County. Thirty-seven percent of the Prince George's population was black in 1980, compared with just under 14 percent in 1970.

The report, compiled by the planning department's research division, is the 10th countywide breakdown of census figures released since the 1980 census.

Phillip Taylor, the planning staff member responsible for the report, said that trends documented by the study indicate that the county's white population has decreased during the 1980s while the black population has continued to grow, but at a slower rate.

White "out migration" placed more middle-income housing on the market for blacks moving to the county from the District in the 1970s, Taylor said.

"In certain areas of the county, we have found that blacks' incomes are much higher than whites," said Taylor, citing the communities of Kettering and Fort Washington as examples of this shift. "That wasn't always the case."

Another finding was that households headed by women accounted for 63 percent of black families below the poverty level in 1980, up from 42 1/2 percent in 1970, the planners said.

Other conclusions:

* Most growth in the black population took place in relatively old communities inside the Capital Beltway, but when it occurred further out, it was in areas such as Largo, Kettering and Fort Washington, where housing is more expensive.

* Black median income more than doubled, from $10,624 per household in 1970 to $22,930 in 1980 -- a 16 percent increase after adjustments for inflation. At the same time, the percentage of black families earning less than $5,000 annually fell from 12 to 5 percent.

* The median age of the county's black population rose from 21 to 25.7 between 1970 and 1980.

One-person black households increased significantly during the decade, from 2,052 in 1970 to 15,224 in 1980. At the same time, households of five or more members decreased markedly.

Labor force participation among blacks rose from 73 1/2 percent in 1970 to 85 percent in 1980, although the unemployment rate for black males remained double that of white males in the same year.

The next census figures are likely to show the county's demographics remaining more stable during the 1980s, Taylor said.

"We have a general idea that the growth of the black population in Prince George's will not be as great as in the decade of the 1970s," he said.

"We'll have to look at the reasons for the growth and see if they still exist." The lifting of the county's moratorium on sewer construction, which was imposed during the 1970s, for example, played a role in an expanded housing market, which made it easier for people to buy homes in the county, he said.

Also, more multi-unit housing has become available in neighboring jurisdictions for low- and moderate-income families, he said.