Objective: To investigate the effects of Hedyotis diffusa polysaccharide extract (HDPE) on endoplasmic reticulum autophagy in laryngeal cancer Hep-2 cells. Methods: The cells were divided into control group, HDPE 100, 200, 400 mg/L group and 3-MA(autophagy inhibitor) group. MTT assay was used to detect the inhibition rate of cell proliferation after 24, 48 and 72 h of culture, and TUNEL was used to detect the apoptosis of cells in each group. The changes of autophages and autophagic lysosomes were observed by MDC staining, and the formation of autophagic vesicles around endoplasmic reticulum was observed by transmission electron microscopy. Western blot was used to detect the expressions of Beclin-1, microtubule-associated light chain protein 3I (LC3I), microtubule-associated light chain protein 3II (LC3II), glucose regulatory protein 78 (GRP78), activated transcription factor 6 (ATF6) and CCAAT enhancer binding protein homologous protein (CHOP) in each group. Results: Compared with the control group, the inhibition rate of cell proliferation and apoptotic index AI in HDPE 100, 200, 400 mg/L group and blocker group were increased, the positive rate of MDC was decreased, and the autophagic vesicles around endoplasmic reticulum were reduced. The expression levels of GRP78, ATF6 and CHOP and the ratio of LC3I/LC3II were increased, and the expression of Beclin-1 was decreased (P<0.05). Compared with 3-MA group, the inhibition rate of cell proliferation and apoptotic index AI in HDPE 400 mg/L group were increased, the positive rate of MDC was decreased, the expressions of GRP78, ATF6 and CHOP and LC3I/LC3II ratio were increased, and the expression of Beclin-1 was decreased (P<0.05). Conclusion: HDPE may inhibit the proliferation of Hep-2 cells by inhibiting endoplasmic reticulum autophagy and promoting the apoptosis of endoplasmic reticulum stress in laryngeal cancer Hep-2 cells.