Objective: To investigate the role of Yes-associated protein 1 (YAP1)-JUN in promoting the proliferation and epithelial mesenchymal transitions (EMT) transformation of laryngeal squamous cell carcinoma. Methods: The expression and subcellular localization of YAP1 were detected by tissue immunofluorescence assay. The effects of YAP1 on the proliferation of laryngeal squamous cell were examined by cell clone formation experiment. Western blot and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) were used to detect the effect of YAP1 on the expression and transcriptional level of EMT-related molecular markers. The interaction between YAP1 and JUN was detected by immunocoprecipitation (CoIP) and Western blot assay, which regulated the expression of downstream genes to control the EMT process. Results: The expression of YAP1 in laryngeal squamous cell carcinoma tissue increased and transferred from cytoplasm to nucleus. The number of clones increased significantly after YAP1 up regulation (P<0.01). The expression level of key gene E-cadherin in epithelial cells was significantly inhibited after YAP1 up (P<0.01), while the expression level of the key genes of interstitial cells, β-catenin, vimentin and N-cadherin was significantly up (P<0.01). YAP1 was interacted with nuclear transcription factor JUN, and the proliferation ability of YAP1 decreased significantly (P<0.01) after the inhibition of JUN expression (P<0.01), and the expression of EMT related molecular markers decreased significantly (P<0.01). Conclusions YAP1 combined with JUN gene promotes the proliferation and EMT transformation of human laryngeal squamous cell carcinoma cells.