Abstract: Objective : To explore the influence of EBP50 (ezrin-radixin-moesin-binding phospho-protein-50) on mi-crofilament cytoskeleton content and distribution in cultured HeLa cells, to investigate the relationship be-tween the changes in microfilament cytoskeleton localization and EBP50 after PDGF (platelet-derived growthfactor) stimulation, and to further clarify the molecular mechanism by which EBP50 suppresses tumor cell pro-liferation and migration. Methods : pBK-CMV-HA-EBP50 wild type recombinant plasmid and pBK-CMV-HAempty vector were transfected into HeLa cells. G418 at 350mg/L was used to screen for cell clones stably ex-pressing EBP50. Western blot was carried out to detect EBP50 expression. Similarities and differences in mi-crofilament cytoskeleton content and distribution in HeLa cells transfected with pBK-CMV-HA-EBP50 wildtype recombinant plasmid or pBK-CMV-HA empty vector were analyzed by Western blot, fluorescence stain-ing and confocal microscopy. HeLa cells stably transfected with the pBK-CMV-HA-EBP50 wild type recombi-nant plasmid and the pBK-CMV-HA empty vector were also treated with PDGF (10 ng/ml and 20 ng/ml, 37℃,15min) and stained by rhodamine-labeled phalloidin to observe the distribution of microfilament cytoskeletonin the two groups. EBP50 protein distribution in PDGF-stimulated HeLa cells was detected by immunofluores-cence. Results : Western blot results confirmed that the EBP50 cDNA fragment could express EBP50 in cul-tured HeLa cell lines and that cell lines stably expressing EBP50 were successfully obtained. Western blotand fluorescence results showed that in the cell line transfected with empty vector, the microfilament cy-toskeleton was thick, loose, multidirectional and displayed crossing arrangements. The content of microfila-ment cytoskeleton in the cell line transfected with pBK-CMV-HA-EBP50 was different from that found in thecell line transfected with empty vector. EBP50 expression enhanced microfilament cytoskeleton polymeriza-tion into compact thin filaments. Under the stimulation of PDGF, EBP50 migrated to the cell membrane fromthe cytosol together with microfilament cytoskeleton and co-localized there. Conclusion : EBP50 can changethe distribution of microfilament cytoskeleton in cultured HeLa cells and can also bind the microfilament cy-toskeleton to the cell membrane under the stimulation of PDGF. EBP50 may play a role in the proliferationand migration of tumor cells by influencing the distribution and localization of microfilament cytoskeleton.