<p>Pterygium syndrome is a common eye disease that often leads to vision loss and even blindness. There is increasing evidence that miRNAs play a key role in the progression of pterygium, but the function of miR-381-3p in pterygium has not been studied. Therefore, this study aimed to investigate the effect of miR-381-3p on the progression of pterygium and to elucidate its potential molecular mechanisms. Human pterygium fibroblasts (HPFs) were isolated from clinical pterygium tissues. The expression of key genes and proteins was detected via RT-qPCR and western blotting. Cell proliferation was detected by CCK-8 and scratch assay, while cell invasion was examined by Transwell assay. Protein interactions were investigated by coimmunoprecipitation. First, we found that the expression level of miR-381-3p was significantly reduced in pterygium tissues. Second, we found that the overexpression of miR-381-3p in HPFs inhibited the proliferation, migration, and invasion abilities of HPFs while inducing cell apoptosis. In addition, in pterygium tissue, the expression of MCPIP1 was downregulated, and the expression of HACE1 and TRIP12 was upregulated. Importantly, MCPIP1 interference partially attenuated the positive effects of miR-381-3p overexpression described above, and miR-381-3p could target HACE1, while HACE1 could bind to TRIP12. Mechanistic studies revealed that miR-381-3p inhibited the binding of HACE1 to TRIP12 through the inhibition of HACE1 expression, thereby inhibiting the ubiquitination and degradation of MCPIP1 and improving the progression of pterygium. Our study highlights the powerful potential of miR-381-3p in improving the progression of pterygium, laying the foundation for the development of new intervention targets for related diseases.</p>