Rhizoma paridis saponins (RPS) played a good antitumor role in many clinical applications. However, low oral bioavailability limited its application. In this research, water extract of Curcuma (CW) significantly increased antitumor effect of Rhizoma paridis saponins (RPS). GC–MS was used to identify its polar composition. HPLC was applied for determination of the content of curcuminoids in CW. As a result, 47 analytes with 0.65% of curcuminoids were identified in CW. According to the in vivo anti-tumor data, the best proportion of curcuminoids in CW with RPS was 16:500 (w/w). Using this ratio, curcuminoids significantly increased absorption of RPS in the everted rat duodenum sac system. In addition, curcuminoids decreased the promotion of RPS on rhodamine 123 efflux. The effect of curcuminoids was similar to that of the P-gp inhibitor, cyclosporin A in combination with RPS. In conclusion, drug combination of water extract of Curcuma with RPS was a good method to increase the antitumor effect of RPS. This combination would be a potent anticancer agent used in the prospective application.