Objective To evaluate the predictive value of pathological tumor cell proportion size(PTS)and invasive lesion classification for recurrence of stage Ⅰ lung adenocarcinoma(LUAD).Methods A total of 160 patients who underwent stage Ⅰ LUAD resection in the hospital from February 2019 to February 2022 were retrospectively enrolled.According to PTS,the patients were divided into a high proliferation group(n=76)and a low proliferation group(n=84).According to the invasive lesion classification,the patients were divided into adenocarcinoma in situ(AIS)group(n=58),minimally invasive adenocarcinoma(MIA)group(n=52)and invasive adenocarcinoma(IAC)group(n=50).Cox proportional hazards regression was used to analyze the influencing factors of recurrence of stage Ⅰ LUAD.Kaplan-Meier was used to analyze the disease-free sur-vival(DFS)of each group,and the statistical power of variable factors was analyzed by receiver operating characteristic(ROC)curve.Results There were significant differences in mean tumor diameter,nodule type,margin condition,spread through air spaces(STAS),TNM stage,maximum tumor diameter,degree of differ-entiation,lymph node metastasis and proliferation cell nuclear antigen(Ki-67)proliferation index among pa-tients with different PTS(P＜0.05).STAS was a risk factor for DFS in patients with different PTS(P＜0.05),and the difference in DFS among patients with different PTS was statistically significant(P＜0.05).DFS in the low proliferation group was higher than DFS in the high proliferation group.PTS combined with STAS had a better efficacy in predicting stage Ⅰ LUAD recurrence[area under the curve(AUC)was 0.748].There were significant differences in mean tumor diameter,nodule type,margin condition,STAS,TNM stage,maximum tumor diameter,degree of differentiation,lymph node metastasis and Ki-67 proliferation index a-mong patients with different invasive lesions(P＜0.05).Margin condition and STAS were risk factors for DFS in patients with different invasive lesion types(P＜0.05).There was a significant difference in DFS be-tween patients with different invasive lesion types(P＜0.05),DFS in AIS group＞DFS in MIA group＞DFS in IAC group.The type of invasive lesions and margin condition combined with STAS had a good predictive value for stage Ⅰ LUAD recurrence(AUC was 0.784).Conclusion Different PTS combined with STAS can predict the recurrence of stage Ⅰ LUAD.Different invasive lesions combined with margin condition and STAS also have important predictive value for the recurrence of stage Ⅰ LUAD.