ABS TRACTBipolar disorder (BPD) is chronic illness which courses with relapses of manic, hypomanic, mix and depressive episodes. Despite BPD is described as a rarely seen disease in children and adolescents, in the present time increasing numbers of children which are having BPD diagnosis contributed to the description, classification and treatment of this disease. It becomes inevitable to evaluate genetic aspects of this disorder after detection of prevalence in children and adolescents, clinical properties of BPD and high frequency of this disorder in relatives of BPD children. It is being mentioned that early-onset BPD patients genetically resemble each other and genetic features take important role in those individuals. In this paper we tried to review articles which were published between years 1998 and 2012, particularly the actual samples. After studies about genes which are relevant to limbic system (such as SLC6A4, 5HTT, HTR2A, DRD2) resulted inconsistency; focusing on calcium channel system of neurons has become more important in recent years. Studies with pediatric age group are rare and it is a necessity to make new researches which aim to explain etiology of bipolar disorder. New molecular genetic researches may contribute to illumination of etiology of BPD.