The herein research was carried out in order to identified the presence of bacteria in cervix and uterine lumen in Iraqi cattle during the different estrus phase with focusing on Protus and E coli. Estrus phases were determined by the structures which found on ovary (follicular growth for pro-estrus, mature growing follicle for estrus, hemorrhagic corpus luteam for meta-estrus and active corpus luteam for di-eatrus). Forty cervical swabs (ten for each estrus phase) and forty uterine swabs (ten for each estrus phase) were taken from macroscopically healthy reproductive animals after slaughtering and cultivated on nutrient agar and blood agar, the bacterial isolation were identified with biochemical teats. The present study found that (65%) of cervical swabs were bacterial positive and the bacterial isolates were higher in the pro-estrus and meta-estrus phases 70% than estrus and diestrus 60%, the Protus spp. Could not been isolated from cervix or uterine during estrus phases, while E coli isolated during three first phases and disappear during diestrus phase, and appear as 10 single and 10 mixed isolated during follicular phase and metaestrus phase in cervical swabs. A total of five different microorganisms were isolated from cervical swabs (Escherichia coli, Streptococcus faecalis, Staphylococcus aureus, Staphylococcus hominies and Staphylococcus epidermidis) with twelve single isolation and fourteen mixed isolation. The present study found that (47.5%) of uterine swabs were bacterial positive and the bacterial isolates were higher in the pro-estrus, estrus and meta-estrus phases 50% than estrus and diestrus 40%, E coli isolated during estrus and diestrus phases only, and appear as 7 single and 2 mixed isolated during those two phases in uterine swabs. A total of five different microorganisms were isolated from uterine swabs (Escherichia coli, Streptococcus faecalis, Staphylococcus aureus, Staphylococcus hominies and Staphylococcus epidermidis) with fourteen single isolation and five mixed isolation.