Objective    To evaluate the effects of celecoxib on tumor growth，COX-2 and survivin expressions and angiogenesis in nude mice.     Methods    Xenograft animal model was established by injecting human colon cancer HT-29 cells into the BALB/c nude mice subcutaneously.  Fifty mice were randomly divided into 4 groups 16 d after injection：control group

celecoxib group（r

eceiving 25

50

75

100 mg·kg

-1

·d

-1

for 35 d）. Tumor volumes were measured every week.  The expression level of COX-2

survivin and the microvessel density (MVD) of the xenograft tumor tissues were measured by immunohistochemistry

and mRNA level of VEGF by RT-PCR.     Results    Celecoxib at dose of 25

50

75 and 100 mg·kg

-1

·d

-1

inhibited the tumor volume by 34.94%

39.20%

53.50%

59.20% respectively

and showed more effective in suppressing the tumor growth than the control group(P0.05).  All celecoxib groups showed a significantly decreased expression of COX-2 and survivin compared with those in the control group (P0.05) and their expression was in a dose-dependent manner. 25 mg·kg

-1

·d

-1

celecoxib inhibited VEGF mRNA expression and angiogenesis as compared with the control group (P0.05)， but not in a dose-dependent manner.     Conclusion    Celecoxib can suppress tumor growth partly by inhibiting survivin expression. Low dose of celecoxib can decrease the angiogenesis of xenograft colon cancer

and furthur more prevent the metastasis of  colorectal cancer.