Uterine artery pseudoaneurysm (UAP) attracted obstetricians' attention recently. In this report, UAP manifested concomitant with or after the abortion of cesarean scar pregnancy (CSP), which is clinically significant. This association has been recently reported elsewhere. The mechanism of the occurrence of UAP is still obscure; however, "weak" vessels or "traumatized" vessels may be an underlying condition. In CSP, the vessels invades deep into the muscles (there are thin decidua), where the vessels may be in a different condition from that of the normal nidation site (placentaion). In fact, CSP, if unterminated, became placenta accrete (increta, percreta). The study on the association between UAP and CSP may solve the mechanism of UAP, and thus, this report is important.