Abstract: 【Abstract】 Objective To investigate the situation of dental heath and oral disease of the pregnant women in the second trimester. Objective To investigate the situation of dental heath and oral disease of the pregnant women in the second trimester. Methods 845 pregnant women who visited our hospital for prenetal examination from Apr.2009 to Aug.2010 were inquired with questionairs and examinated clinically. Results The incidence of tooth decay,gingivitis and periodontis was 43.67%,84.38% and 8.28% respectively.The incidence of prepregnancy oral health care was only 22.2%.Food debris and dental tartar were the main causes of gingivitis and periodontis. Conclusions It is important to strengthen oral health education for prepregnant and pregnant women.