The number of persons living in poverty in the United States in 1977 was 24,720,000 or 11.6 percent of the population, the Census Bureau says in its official report on poverty for 1977.

The figure for 1976 was 11.8 percent so the proportion of persons in the poverty barely changed over the last year, Census officials said. However, has dropped susbtantially over the past generation. In 1959, it was 22.4 percent.

Although the overall poverty percentage was 11.6 percent, it was far higher for blacks, 31.3 percent, and Hispanic, 22.4 percent.

The high poverty figures for blacks reflect it part the large percentage of black families without a father present - 39 percent in 1977 compared with 12 percent of white families without fathers present. Female workers in virtually all categories make less than male, so any group with a large percentage of female-headed families is likely to have far lower income.

However, even where a male head-of-family was present, the median for black families was less than for whites - $13,443 compared with $17,348.

The poverty figures reflect only pre-tax cash income and do not include the value of food stamps, free health benefits and subsidized housing. Officials said the poverty percentage would be less than 11.6 percent if billions of dollars paid out in these in-kind benefits were factored in.

The census figures show that median income for all families was $16,009. For unrelated individuals, the median was $5,907.

Although the median has been rising for the past several years, in real dollars it was actually higher in 1973, a boom year when it reached $16,433 for families, measured in terms of 1977 dollars' spending power.