Objective To investigate the effect of LINC00839 targeting regulation of miR-124-3p expression on the biological behavior of bladder cancer cells. Methods Quantitative real-time PCR (qPCR) was used to detect the expression of LINC00839 in bladder cancer and adjacent normal tissue, and bladder cancer cell lines T24, 5637 and EJ. Three small interfering RNA-LINC00839 (si-LINC00839-1, si-LINC00839-2 and si-LINC00839-3) sequences were constructed to transfect bladder cancer cells. After silencing the expression of LINC00839, CCK-8 was used to detect the effect of LINC00839 on cell proliferation. Transwell was used to detect the effect of LINC00839 on cell invasion. The effect of LINC00839 on cell apoptosis was detected by flow cytometry. The interaction between LINC00839 and miR-124-3p was detected by double luciferase assay. Immunoblotting was used to detect the effect of LINC00839 inhibition on endothelial receptor B (EDNRB) protein expression. Results qPCR results showed that the expression of LINC00839 increased significantly in bladder cancer tissue than that in adjacent normal tissue (P＜0.05). LINC00839 had the highest expression in bladder cancer 5637 cells. Among three siRNA sequences, si-LINC00839-2 had the highest inhibition efficiency and was used as the experimental group. Compared with the si-NC group, cell proliferation rate, invasion number and apoptosis rate were decreased in the si-LINC00839-2 group (P＜0.05). Dual luciferase assay results showed that there were complementary binding sites between LINC00839 and miR-124-3p. Compared with the si-NC group, si-LINC00839-2 group showed the up-regulated expression of miR-124-3p and inhibited expression of EDNRB protein (P＜0.05). Conclusion LINC00839 can target miR-124-3p to regulate the biological behaviors of migration, invasion and apoptosis on bladder cancer cells. [ABSTRACT FROM AUTHOR]