Objective:To investigate the effects of miRNA-143-3p on the proliferation, migration and invasion of keloid fibroblasts (KFB) and the possible mechanism.Methods:KFB and normal skin fibroblasts (NFB) were isolated and cultured. The expression of miRNA-143-3p and integrin β5 (ITGB5) at mRNA level in KFB and NFB were detected by RT-qPCR. Western blot was performed to measure the expression of ITGB5 at protein level. After overexpressing miRNA-143-3p or suppressing ITGB5 expression in KFB cells, MTT assay, Transwell assay, RT-qPCR and Western blot were used to detect the effects on the proliferation, migration and invasion of KFB and the expression of related proteins. Dual-luciferase reporter gene assay was used to validate the targeting relationship between miRNA-143-3p and ITGB5.Results:Compared with NFB, KFB showed down-regulated miRNA-143-3p expression and up-regulated expression of ITGB5 at both mRNA and protein levels. The proliferation, migration and invasion of KFB were inhibited after overexpressing miRNA-143-3p or suppressing ITGB5 expression. Moreover, miRNA-143-3p could negatively regulate ITGB5 expression and overexpression of ITGB5 reversed the effects of miRNA-143-3p overexpression on KFB proliferation, migration and invasion.Conclusions:This study suggested that miRNA-143-3p could inhibit the proliferation, migration and invasion of KFB through down-regulating ITGB5 expression.