Objective To investigate the effect and mechanism of lncRNA PCAT19 on the proliferation， migration and invasion of oral squamous cell carcinoma HSC3 cells. Methods The cancer tissues and adjacent tissues of 45 patients with oral squamous cell carcinoma were collected，and the expression of PCAT19 and miR⁃ 769⁃5p in the tissues was detected by qRT⁃PCR. HSC3 cells were cultured in vitro and transfected with PCAT19 siRNA or miR⁃769⁃5p mimic，or co⁃transfected with PCAT19 siRNA and miR⁃769⁃5p inhibitor. Then cell prolifera⁃ tion was detected by CCK ⁃8 method and clone formation assay. Scratch assay and Transwell assay were used to detect cell migration and invasion，respectively. Western blotting was used to detect the expression of E⁃cadherin and N⁃cadherin protein in the cells. The dual⁃luciferase reporter gene experiment was done to verify the regulatory relationship between PCAT19 and miR ⁃769⁃5p. Results The expression of PCAT19 in the oral squamous cell carcinoma was higher than that in the adjacent tissues，but the expression of miR⁃769⁃5p was lower than that in the adjacent tissue，（P < 0.05）. Interfering with PCAT19 or overexpressing miR⁃769⁃5p decreased the OD value，colony formation number，scratch healing rate，invasion number and the expression of N ⁃cadherin protein in the HSC3 cells（P < 0.05），but promoted the expression of E⁃cadherin protein（P < 0.05）. PCAT19 could target and nega⁃ tively regulate miR ⁃ 769 ⁃ 5p. Downregulation of miR ⁃ 769 ⁃ 5p reversed the effects of interfering with PCAT19 on HSC3 cells proliferation，migration and invasion. Conclusion The expression of PCAT19 is up⁃regulated in oral squamous cell carcinoma tissues，and interfering with PCAT19 may inhibit the proliferation，migration and inva⁃ sion of oral squamous cell carcinoma HSC3 cells by targeting up⁃regulated miR⁃769⁃5p.