Abstract: Objective To explore the influencing factors of diabetic nephropathy.Methods A 1:1 sex and age matched case control study was conducted among 139 type 2 diabetic nephropathy(DN) patients.Information was collected through interview for demog raphic data,disease history,family disease history,die tetic habit,behavior pattern,social psychologic character,clinical data and laboratory data.Polymo rphism of methylenete trahydro folate(MTHFR) gene was assessed with polymerase chain reaction(PCR) and restriction fragment length polymorphism(RFLP).The effects of risk factors on DN in type 2 diabetes patients and the potential interaction between the risk factors were analyzed with conditional logistic regression model.Results Univariate conditional logistic regression analysis showed that 667Ta llele of MTHFR gene,long diabetes history,diabetic retinopathy,lower ratio of albumm/globulin(A/G),higher fibrinogen were associated with higher risk of DN incident.Higher education,more exercise,control of sugar intake,higher vegetable in take after DM incident were associated with lower risk of DN incident.The interaction existed between duration of DM and geno type,vegetable in take and exercise,vege table in take after DM.Conclusion The incidene of DN of type 2 diabetes patient is associdted with multiplerisk factors.