Objective To research the relationship between neonatal weight and puerpera folic acid intake and dietary with other factors. Method Self-designed questionnaire was applied to 216 puerpera of people's in hospital by anonymous survey. Results 1)Puerperaes weekly taking fruit frequency was different,the difference in neonatal weight change was statistically significant (P=0.011);2)The difference in neonatal weight change among taking different vegetable quantities was statistically significant (P=0.014);3)The difference in neonatal weight change among puerperaes taking different meat quantities was statistically significant (P=0.001);4)The difference in neonatal weight change among puerperaes taking soy maternal of different times per week was statistically significant by analysis (P=0.000);5)Whether puerperaes taking folic acid about three months before pregnancy or during pregnancy period or not had an influence on infant birth weight(P=0.027);6)The result of the multiple linear regression analysis was that the infant birth weight might be affected by the times of intaking vegetable,meat,beans and nuts. Conclusion A balanced diet and nutrition enough and reasonable taking folic acid effectively prevent low birth weight.