Objective:This study aims to observe the changes of miRNA-199a-5p expression in human skin fibroblasts with thermal injury and its effects on the proliferation,migration and invasion of skin fibroblasts. Methods:Cell models of thermal injury were established using human skin fibroblast cell line by bathing in water at 52℃ for 30 s and 60 s,respectively,and the thermal injury of cells was observed and compared. The proliferation rate of cells 24 h and 48 h after thermal injury was detected by MTT assay. The changes of miRNA-199a-5p expression in the cells 24 and 48 h after thermal injury were determined through qRT-PCR. Cell migration and invasion were detected using wound-healing assay and Transwell assay. The expression of miRNA-199a-5p in thermally injured cells was increased using mimics,and the proliferation and invasion of thermally injured cells were detected. Results:Bathing in water at 52 ℃ for 30 s could successfully establish a thermal injury model in human skin fibroblasts. After thermal injury,miRNA-199a-5p expression was down-regulated[24 h,(2.67±0.35)%,P<0.001;48 h,(18.42±0.44)%,P<0.001],cell proliferation was significantly inhibited[24 h,(17.10±3.21)%,P<0.002;48 h,(25.93±1.74)%,P<0.001],cell migration decreased significantly[(35.35±7.07)%,P<0.001],and cell invasion was also significantly inhibited[(57.14±9.52)%,P<0.007]. After enhancing miRNA-199a-5p expression in the thermally injured cells using mimics,the proliferation of the cells increased significantly[(136.55±6.14)%,P<0.003],and the invasion ability of the cells was enhanced[(136.55±6.14)%,P<0.003]. Conclusion:The expression level of miRNA-199a-5p in human skin fibroblasts with thermal injury is positively correlated with cell proliferation,migration and invasion. Increasing the expression level of miRNA-199a-5p in thermally injured cells can help it rapid return.