Objective:To investigate the inhibitory effect of the water-soluble preparation of curcumin on tumor angiogenesis induced by alginate-encapsulated colon carcinoma C26 cell line in mice. Methods: The water-soluble preparation of curcumin was made by forming inclusion compound of curcumin with hydroxypropyl-?-cyclodextrin (C-HP-?-CD). Subcutaneous imbedding of alginate-encapsulated colon carcinoma C26 cells was used to create tumor bearing model in BALB/c mice. Then the mouse models were intraperitoneally injected with C-HP-?-CD, TNF-70 (as positive control), or HP-?-CD(as negative control). The angiogenesis in the alginate beads was observed under light microscope, floresencent microscope, and transmission electron microscope. The fluorescein isothiacyanate-dextran (FITC-Dextran) tracing technique was used to observe the inhibitory effect of the inclusion compound of curcumin on angiogenesis induced by colon carcinoma C26 cells in alginate beads.Results: The C-HP-?-CD and the mouse model of subcutaneous alginate-encapsulated colon carcinoma C26 cells were successfully created. Transmission electron microscope showed angiogenesis in alginate-encapsulated colon carcinoma C26 cells; claval endothelial cells were seen in some lumens. Optical microscope and the fluorescence microscope showed that the angiogenesis density of the positive group and curcumin groups were obviously lower than those of the negative control group; no obvious difference at vessel morphosis was found among the 3 alginate-encapsulated groups. FITC-Dextran tracing technology found that the fluorescent intensity of the negative control group was significantly higher than those of the positive control group and the curcumin group (P