Abstract: ObjectiveTo study the influencing factors and the interactions of the factors between family history and environmental of congenital malformation;to putforward the key intervention factors by quantitative analysing the action intensities and population attributable risk(PAR%)of the controllable factors.MethodsA case-control study was carried out with 185 congenital malformation cases and 185 not taking cong enital malformation controls gathered by cluster sampling in Shandong.All of the data were analysed with simple and multiple unconditional Logistic regression models.ResultsThe risk factors of congenital malformation were positive congenital malformation family history(OR=3.466,95% CI:1.702~7.062),fever during early stages of pregnancy(OR=2.743,95% CI:1.171~6.421),nutrition during early stages of pregnancy(OR=3.074,95% CI:1.676~5.740),negative life events stimulus during pregnancy(OR=1.837,95% CI:1.002~3.366),and cytomegalo virus infection in preg nancy.There were positve interactions between positive congenital malformation family history and other environmental influencing factors.ConclusionCongenital malformation was caused by multiple influencing factors.There were positive additive model inter actions between positive congenital malformation family history and some environmental factors.When the controllable factors are intervened in high-risk population with positive family history,the decrease of risk of congenital malformation can reach in general population.