The purpose of this study was to investigate the level of involvement on infant care after transition to parenthood in dual earner families, and to explore the associated variables affecting on infant care involvement. For this purpose, the empirical sample testing was conducted using structured questionnaires with 197 dual earner couples. The major findings were as follows : First, in general, wive`s level of involvement on infant care was higher than that of husbands. Second, the traditional sex role attitude limits the level of involvement on infant care of husband. Third, in case of husbands, wives` age, degree of job importance have some effect on level involvement. For wives, however, the perceptions of services support to infant care and sex role attitude affected the level of infant care involvement. So the sex role attitude is the most influential common factor for couples.