Abstract: Objective To investigate the current status of the dental health of pregnant women and to understand the development of oral diseases with pregnant progress. Methods Totally,2149 systemically healthy pregnant women were enrolled in the study.Their dental health status including dental caries,teeth material alba,odontolith and periodonititis were registered.Also,relationship of the above oral diseases with different trimesters was analyzed. Results The conditions oral cavity of these pregnant women was worse with higher detection rate of teeth material alba[98.0%(2106/2149)]and odontolith[90.0% (1934/2149)].The incidence of severe gingivitis and advanced stage periodontitis were higher in the third trimester than in early or mid trimester (severe gingivitis:2.8%vs 0.7% and 1.3%;advanced stage periodontitis:15.8% vs O and 7.9%,P<0.05). Conclusions The dental health status is worse during pregnancy.Streghthening the public health education on dental hygiene is necessary for early prevention,identification and management of oral diseases.