The research conducted deals with the problem of development of personal maturity in adopting parents. The objectives of the research are to describe the content foundation of the adopting parents' personal maturity represented by motivational and value-related, emotional, cognitive and activity-related components, to prove the influence of personal maturity of adopting parents on the efficiency of adoption parenting. Based on the analysis of theoretical and methodological standpoints and the empirical data obtained, the particularities of personal maturity of adopting parents are represented. The content foundation of adopting parents' personal maturity is considered. The study was conducted during the adaptation period of children entering the adopting family. The respondents were 40 adopting parents aged 30 to 57 and 35 adopted children aged 7-15. The results of the study have allowed revealing the key particularities of the adopting parents' personal maturity ensuring not only the efficiency of adoption parenting but also acting as a condition of preventing the social orphanage.