Aim of Work: The aim of the present study was to use color Doppler sonography to confirm the hypothesis that CIUD induced bleeding is secondary a decrease of uterine artery resistance and increase in the uterine artery blood flow and to determine whether transvaginal color Doppler could be used to identify patients at risk of developing abnormal uterine bleeding after CIUD insertion. Material and methods: This Study includes 93 patients divided into three groups. Group I; included 32 women using copper intrauterine device (CIUD) (Tcu-380A) and complaining of menorrhagia or menometrorrhagia. Group II; included 30 women using (CIUD) and not complaining of abnormal uterine bleeding. They attended outpatient clinic complaining of vaginal discharge or inability to fell the threads of (CIUD) or requesting (CIUD) removal. Group III; included 31 women attended outpatient clinic complaining of vaginal discharge or requesting (CIUD) insertion, and not complaining of abnormal uterine bleeding.Results: As regard to Doppler findings, it was noted that RI was significantly lower in group I in comparison to group II (P< 0.001). Also RI was significantly lower in group I in comparison to group III (p< 0.001). There was no significant difference between group II and group III (control group) regarding RI (P = 0.844, and = 0.839, respectively).Conclusion: The results of our study revealed that PI and RI were significantly lower in women with CIUD-induced abnormal bleeding than in those using CIUD without complaining of abnormal vaginal bleeding or in women not using any form of contraception. The results of our study confirmed the hypothesis that there is increase in uterine artery blood flow (indicated by decreased PI and RI) in patients with CIUD induced abnormal vaginal bleeding. In addition, detection of PI and RI in the uterine artery could be used to identify patients at risk of developing excessive bleeding after copper IUD insertion.