Pregnancies of unmarried women are one of the most serious sex problems because they can negatively affect the lives and development of both unwed mothers and their extramarital children. The number of unwed adolescent mothers is growing recently, extending the seriousness of the problem. This study was conducted to explore the ego-state, life position and family systems that may cause unmarried pregnancy. The data obtained from the structured questionnaire survey of 79 unmarried adolescent mothers and 82 female adolescents were analyzed in terms of frequency and t-test using the SPSS WIN 8.0 program. The results were as follows: 1. Ego-state elements of unmarried adolescent mothers were distributed evenly in general and this falls under the All B(BBBBB) type of ego-gram, just like the adolescents. As for the subject adolescent mothers, CP was the lowest among the 5 egos. 2. As to the life position, the position of "I′m OK, You′re OK"was the highest for both groups, with slight differences. 3. With regard to the family system types sorted by the combination of family cohesion and family adaptability levels, both the adolescent. mothers and adolescents tended to perceive their families as somewhat-balanced or balanced families. 4. While the two groups of adolescent mothers and adolescents showed, on the whole, the same types for all the indicators like above, statistically significant differences were found in more detailed elements.