Objective To understand the status and influencing factors of the early, middle and late pregnant women's dietary behavior in Chengdu, so as to provide a reference for the development of targeted health education.Methods A self-made questionnaire was used to investigate the dietary behaviors of 600 pregnant women in early, middle, late stage of pregnancy from 4 hospitals in Chengdu. Data entry was carried out by EpiData software, and analyzed by Chinese version of statistical software SPSS 17.0. Results The status of dietary behavior of women in different stages of pregnancy was generally good. However, there were still unhealthy eating behaviors, such as partial food, excessive intake of fruit and milk, smoking and drinking alcohol. The knowledge of dietary behaviors was mainly from families, friends, newspapers and magazines. The results of the structural equation modeling showed that the dietary behavior of pregnant women was influenced by behavioral intentions, and the standardization regression coefficientβ was 0.301. Behavioral attitudes and subjective norms affected dietary behavior by influencing behavioral intentions, withβ values of 0.131 and 0.647 respectively. The education degree of pregnant women influenced dietary behavior directly (β=0.226); family per capita income affected eating behavior by influencing behavior attitude (β=0.168); and the mother's education degree affected dietary behavior by influencing subjective norms (β=0.217).Conclusions The dietary behavior of pregnant women is generally good, but there are still some unhealthy eating habit. We should give full play to the role of medical and health personnel, give health education of pregnancy diet, and change the unhealthy dietary behaviors by changing the diet related attitudes of pregnant women and their family members.