Objective To investigate the effect and potential mechanism of microRNA (miRNA)-377 on high glucose-induced proliferation and inflammation in human mesangial cells. Methods Cells were randomly divided into six groups: control group (5.5 mmol/L glucose), high glucose group (30.0 mmol/L glucose), negtive miRNA inhibitor transfection+high glucose group, negtive miRNA mimic transfection+high glucose group, miRNA-377 inhibitor transfection+high glucose group (miR-377i+high glucose group), miRNA-377 mimic transfection+high glucose group (miR-377m+high glucose group). miRNA-377 expression was detected by real-time PCR. Cell proliferation and cell cycle were detected by BrdU assay and flow cytometry, respectively. The release of tumor necrosis factor-α (TNF-α), interleukin (IL)-18, IL-6 and macrophages chemotaxis protein-1 (MCP-1) were evaluated by ELISA. The activations of NF-κB pathway, including the expressions of phosporylated (p)-IκBα, p-P65 and nuclear P65, were measured by Western blotting. Results Compared with those in control group, in high glucose group cell viability, miRNA-377 expression and cell proliferation rate increased (all P<0.05), proportions of S phase cell and G2/M phase cell in cell cycle increased (all P<0.05), the levels of TNF-α, IL-18, IL-6 and MCP-1 were higher (all P<0.05), as well as the expressions of p-IκBα/IκBα, p-P65/P65 and nuclear P65 were increased (all P<0.05). Compared with high glucose group, cell proliferation rate was restrained (P<0.05), proportions of S phase cell and G2/M phase cell in cell cycle was descreased (all P<0.05), the levels of TNF-α, IL-18, IL-6 and MCP-1 were lower (all P<0.05), as well as the expressions of p-IκBα/IκBα, p-P65/P65 and nuclear P65 were reduced (all P<0.05) in miR-377i+high glucose group. However, miR-377m+high glucose group presented opposite results (all P<0.05). Conclusions miRNA-377 knockdown can partially suppress high glucose-induced human mesangial cell proliferation and cell cycle transition, and restrain inflammatory molecules release. Its mechanism may be related to the inhibition of NF-κB pathway.