Abstract： Objective To investigate the clinical efficacy and safety of aminoketone valeric acid photodynamic therapy(ALA-PDT)combined with liquid nitrogen cryotherapy in the treatment of non melanoma skin cancer(NMSC).Methods 78 NMSC patients were selected and randomly divided into 2 groups,with 39 patients in each group.The control group received ALA-PDT treatment,while the observation group received liquid nitrogen cryotherapy for 3 months.Compare the clinical efficacy,sero-logical indicators,and safety between two groups.Results The total effective rate of the observation group was higher than that of the control group,and IL-1 was observed after treatment β、TGF-[3 The level of 1 was lower than that of the control group,with statistical differences(P＜0.05);There was no statistically significant difference in safety between the 2 groups(P＞0.05).Con-clusion ALA-PDT combined with liquid nitrogen cryotherapy can improve the therapeutic effect of NMSC and reduce IL-1 β、TGF-β 1 level,is safe and reliable.