Objective To investigate the value of local progression-free survival (LPFS) for evaluating the local long-term outcome of peripheral lung cancer treated by cyberknife.Methods Retrospective analysis was performed on the clinical records of 81 cyberknife-treated lung cancer patients (90 foci),including 43 primary lung cancer patients (43 foci) and 38 metastatic lung cancer patients (47 foci).Of all the patients,58(63 foci) were treated at a dose of 60 Gy/3 fractions (20 Gy/fraction),and 23 (27 foci) at a dose of 54 Gy/3 fractions (18 Gy/fraction).The short-term treatment outcome and LPFS were used as the indices for observation;a logistic regression was used for analyzing the predictive value of LPFS for local long-term treatment outcome.Results After the evaluation of short-term treatment outcome,63％ of all the foci needed further evaluation.As the follow-up lasted,the number of foci which needed further evaluation decreased,most rapidly during 0.5-2 years after treatment.Re-evaluation results had predictive value for the treatment outcome in the subsequent follow-up,but the predictive value declined as the follow-up lasted.Conclusions LPFS is a recommendable index for evaluating the local outcome of primary or metastatic lung cancer treated by cyberknife,and it also has predicative value for local long-term treatment outcome.