The following are some of the findings based on the results of the annual survey of marital and family characteristics of workers: (1) about 27.6 million of 62.7 million children had mothers in the labor force (over 2 million more than in March 1970); (2) 1.1 million of 6.5 million children under six were in families headed by women (71 percent more than in 1970); (3) the number of children in two-parent families has decreased since 1970; (4) families with working mothers had fewer children; and (5) children whose mothers were employed were families with considerably higher incomes. More black children (48 percent) than white children (38 percent) in two-parent families had employed mothers. Three tables include the following information: (1) number of children under 18 years old, by age, type of family, mother's labor force status, and race, in March 1970 and March 1975; (2) number of families and average number of own children under 18 years old, by type of family, mother's labor force status, and race, in March 1970 and March 1975; and (3) number of children under 18 years old, median family income in 1974, type of family, parents' labor force status, and race, in March 1975. (Author/EC)