Background : Lutein, a xanthophyll, consists of chains with 8 conjugated double bounds containing closed rings on each end of the chain. This carotenoid is found in fruits and vegetables, especially dark green leafy vegetables such as green tea. In this study, we investigated the anticancer effects of purified lutein from green tea on human cancer cell lines containing prostate carcinoma cancer cells (LNCaP). Methods and Results : Prostate carcinoma cancer cells (LNCaP) were cultured and evaluated the inhibitory effect of lutein isolated from green tea compared other carotenoids (β-carotene and lycopene) on cell proliferation. Cyclin D1 and PCNA were evaluated as cell differentiation. In results, PCNA/cyclin regulates the initiation of cell proliferation by mediating DNA polymerase. Under cultural conditions, lycopene remarkably suppressed the PCNA expression prostate cancer cell line LNCaP in higher doses (20 μM - 100 μM) statistically. However, β-carotene and lutein presented the less inhibitory effects on PCNA expression. Determination of PCNA expression in control and treated cells demonstrates that lycopene did affect proliferation in LNCaP cancer cells in dose-dependent manner. However, β-carotene and lutein suppressed the cyclin D1 expression in dose-dependent manner but no in lycopene group. These results indicate that differ carotenoids presented the various suppressive ability of PCNA and cyclin D1 expression in cell proliferation. Conclusion : In conclusion, lutein suppressed the carcinogenesis of induced prostate cancer cell line by acting as a suppressor for inhibiting the expression of cyclin D.