Objective To investigate the effects of keratin 4 (KRT4) overexpression on the viability, proliferation, migration, invasion and apoptosis of laryngeal cancer cells.Methods The overexpressed KRT4 plasmid was constructed and transfected into TU177 laryngeal cancer cells. The experiment was divided into three groups:CON group (blank control group, non transfected), Oe-NC group (negative control group, transfected empty vector of control plasmid), and Oe-KRT4 group (target gene experimental group, transfected KRT4 overexpression plasmid). The transfection efficiency was verified by RT-qPCR and Western blot. The effects of KRT4 overexpression on the viability, proliferation, migration, invasion, and apoptosis of laryngeal cancer cells were detected by CCK-8 assay, plate cloning experiment, cell scratch experiment, Transwell cell invasion experiment, and flow cytometry.Results The results of RT-qPCR and Western blot showed that the expression levels of KRT4 mRNA and KRT4 protein in the Oe-KRT4 group were significantly higher than those in the CON and Oe-NC groups, and the difference was statistically significant(P＜0.000 1). The results of CCK-8 assay showed that the cell viability of the Oe-KRT4 group was significantly reduced compared with the CON group and Oe-NC group, with a statistically significant difference (P＜0.000 1). The results of the plate cloning experiment showed that the number of clones in the Oe-KRT4 group was significantly lower than that in the CON group and Oe-NC group, and the difference was statistically significant (P＜0.000 1). The results of the cell scratch experiment showed that the migration rate of the Oe-KRT4 group was significantly lower than that of the CON group and Oe-NC group, and the difference was statistically significant (P＜0.000 1). The results of cell scratch test indicated that the mobility of Oe-KRT4 group was significantly lower than that of CON group and Oe-NC group, and the difference was statistically significant (P＜0.000 1). The results of Transwell cell invasion experiment showed that the number of cell penetration in the Oe-KRT4 group was significantly lower than that in the CON and Oe-NC groups, and the difference was statistically significant(P＜0.000 1). The results of flow cytometry showed that the apoptosis rate of the Oe-KRT4 group was significantly increased compared with CON group and Oe-NC group, and the difference was statistically significant(P＜0.000 1).Conclusions Overexpression of KRT4 can significantly inhibit the vitality, proliferation, migration, and invasion of laryngeal cancer cells, and promote apoptosis of laryngeal cancer cells. Therefore, KRT4 is expected to become a potential target for the treatment of laryngeal cancer.