Abstract: Objective: To explore the self-identity development of adoptees to be affected by their adoption experiences. Methods: Qualitative research method and in-depth interviews with two female undergraduates about their subjective experience. Conclusion: （1） self-identity was accompanied with adoptees' entire development process, separation with parents after birth, awareness of adoption in childhood, and continued involvement in traumatic life events related with original and adoptive families when adolescence so that the adoptees have inherent self-doubt and insecurity; （2）Adoption happened in close families so adoptees were troubled by self identity of"whose daughter I am", such as title confusion, disliking filling out forms about family relationship and the feeling of belonging to two families; （3）The adoptees had feelings of self-denial and were mal-treated in adoptive families as nemesis because of her gender, which also inspired their unceasing efforts and good academic achievement;（4） The adoptive and original families have blood ties so the adoptee's self-identity shows the characteristics of family identity.