Objective: To study the current status of the knowledge, attitude and demands of birth defect prevention among the pregnant women in Gulou district of Nanjing city in order to provide the support for the first-level prevention of the birth defect based on community. Methods: A questionnaire survey was made among the pregnant women who build card of perinatal health during March 2008 to July 2009 in Gulou district of Nanjing city. Results: 3858 questionnaires were collected in the investigation. The utility questionnaires added up to 3777, and effective rate was 97.90%. The investigation indicated that the levels of the knowledge of birth defect prevention among the pregnant women were 7.33%~99.05%. The levels became higher as the pregnant women with higher education (P<0.05) except two items. 96.64% pregnant women had a keen demand for learning eugenics knowledge. 88.03% understood something about eugenics knowledge, and the main way was newspapers, magazines and books. Conclusion: The pregnant women had incomplete knowledge about birth defect prevention. Most women had a demand for learning eugenics knowledge. The extent and depth of the pregnant women’s health education should be magnified.