Objective To observe the repairing effect of Carthamin on the inhibition of cell migration induced by modeled microgravity（MMG）and its mechanism.Methods The proper concentration of Carthamin was got with MTT assay.The human umbilical vein endothelial cells（HUVECs）were cultured and were divided into the normal gravity（NG）control group

MMG group and MMG+Carthamin group.Transwell was used to detect cell migration.Confocal microscopy and image analysis were used to analyze the modifications of the cytokeratin network and FAs structure.Results Comparing with the NG group

the number of cell migration was significantly decreased in the MMG group （P<0.01）.Comparing with the MMG group

the number of cell migration was significantly increased in the MMG+Carthamin group（P<0.05）.In the NG group

F-actin was obviously polarized and microfilaments were assembled into a bundle.The cytoskeleton of HUVECs was refined

F-actin polarization was significantly decreased and microfilaments staining showed diffuse in the MMG group.Comparing with the MMG group

the F-actin of HUVECs was orderly arranged

pseudopodium was increased and the directivity was enhanced in the MMG+Carthamin group.Comparing with the NG group

the number of FAs（VN）and area（VA）and distance（DS） to cell edge in the MMG group were significantly decreased（P<0.05）.Comparing with the MMG group

the VN

VA and DS were significantly increased in the MMG+Carthamin group（P<0.05）.Conclusion Carthamin could repair the blocked HUVECs migration induced by MMG and it is associated with refinement of F-actin and FAs structure.