The conjoined twins stuck together and often share some organs, and are almost always the same sex. The cause of the conjoined twins still poorly understood, while the probability of their survival is very low. the authors proceed to study the pathological lesions in three conjoined twin pairs: Thoraco-omphalopagus (TOP), Dicephalic parapagus (DCP), Thoraco-abdominopagus (TAP).