Abstract:【Abstract】Objective: This study aimed to detect the expression of P-gp in pediatric hodgkin lymphoma,nonhodgkin lymphoma and Nephroblastoma,which can provide a theoretical basis for individual chemotherapy in clinical. Methods:Immunohistochemistry was performed to detect the expression of P-gp in pediatric tumors(26HL,24NHL and 32WT), and we can evaluated the relationship between P-gp and the clinical characteristics of tumors. Results: (1)The positive expression rates of P-gp was 57.7%,70.8%,65.6% in HL, NHL and WT.(2)There was no significant difference among HL and NHL(P=0.39),WT and adjacent normal tissues(( P=1.00) about the positive expression rates of P-gp.(3) The positive expression rates of P-gp was closely related to clinical stage, LDH, lymphnode metastasis in HL(P=0.03, P=0.05), and was related to the clinical stages in NHL(P=0.02). There was no significant correlation between the espression of P-gp with histological type, clinical stage, lymphnode metastasis, and preoperative chemotherapy time. Conclusion: (1)The high positive expression of P-gp correlate with tumor resistant of HL, NHL and WT, and there is one of unfavorable factors in prognosis.(2) According to resistance protein expression,we can better choice chemotherapy drugs in clinical, in orde to the tumor children use sensitive durg.