Virginia's per capita personal income increased 12.5 percent in 1979, staying ahead of the year's 11.3 percent inflation rate, according to a recently released report by the University of Virginia's Tayloe Murphy Institute.

The state's per capita income is 2 percent below the national average, the report said, but 13 percent above the average for the Southeast. The report showed an average increase of $922 statewide.

The figures, which measure personal income before personal property and income taxes are deducted but after deductions of Social Security and other social insurance program taxes, vary greatly across the state. Not surprisingly, the highest per capita income was found in the Northern Virginia suburbs of Washington, D.C., led by Arlington County at $16,027 per capita, 83 percent above the national average. The lowest was $4,783 per capita, 46 percent below the national average, in Greensville County.

Similarly, the top per capita incomes for cities were led by four Northern Virginia communities, with Falls Church No. 1 at $15,480, followed by Alexandria, Fairfax City and Manassas. The lowest was Buena Vista, with a per capita income of $6,621.

Localities within Virginia's Standard Metropolitan Statistical Areas, which have 66 percent of the state's population, accounted for 72 percent of the state's total personal income. The personal income within the SMSAs showed the highest figure to be $12,141 in the Northern Virginia suburbs. The Richmond area was second with a $9,741 per capita income, and the Roanoke area was third with $8,770. The lowest figure for an SMSA was $6,346 for the Virginia portion of Johnson City-Kingsport-Bristol.

The report was compiled by Dr. John L. Knapp, research director of Tayloe Murphy's Economics Studies Center and by David C. Hodge, a research economist. The institute is part of the Colgate Darden Graduate School of Business Administration.