Background Recombined humanized endostatin (Rh-endostatin) exhibits a potent anti-cancer effect involving multiple molecular targets and signaling pathways. HMGB1 is a highly conserved DNA-binding protein involved in cancer development. The therapeutic effect of Rh-endostatin on HMGB1 has not been reported, thus we investigate the effect in non-small cell lung cancer (NSCLC) cells. Methods Quantitative real-time PCR and Western blot were used to analyze the messenger RNA and protein expression of HMGB1 in A549 cancer cells, while enzyme-linked immunosorbent assay was used to detect the release of HMGB1. Western blot was performed to evaluate HMGB1 expression in SK-MES-1 and H661 NSCLC cells. Results Rh-endostatin inhibited the proliferation of A549 cancer cells and distinctly downregulated the expression and release of HMGB1 in dose and time dependent manners. Rh-endostatin-induced HMGB1 downregulation was confirmed in different types of NSCLC cells. Conclusion These results demonstrate the general phenomenon that Rh-endostatin can induce HMGB1 suppression in a variety of NSCLC cells. Rh-endostatin may suppress HMGB1 expression and release in A549 cancer cells, thus inhibiting cell proliferation.