AIM:Transforming growth factor(TGF)β_1 is involved in avariety of important cellular functions,including cell growthand differentiation,angiogenesis,immune function andextracellular matrix formation.However,the role of TGF β_1as an angioganic factor in colorectal cancer is still unclear.We investigate the relationship between transforming growthfactor β_1 and angiogenesis by analyzing the expression oftransforming growth factor(TGF)β_1 in colorectal cancer,aswell as its association with VEGF and MVD.METHODS:The expression of TGF β_1、VEGF,as well as MVDwere detected in 98 colorectal cancer by immunohistochemicalstaining.The relationship between the TGF β_1 expression andVEGF expression、MVD was evaluated.To evaluate the effect ofTGF β_1 on the angiogenesis of colorectal cancers.RESULTS:Among 98 cases of colorectal cancer,37 werepositive for TGF β_1(37.8%),35 for VEGF(36.7%),respectively.The microvessel counts ranged from 19 to 139.8,with a mean of 48.7(standard deviation,21.8).Theexpression of TGF β_1 was correlated significantly with thedepth of invasion,stage of disease,lymph nodemetastasis,VEGF expression and MVD.Patients in T3-T4,stage Ⅲ-Ⅳ and with lymph node metastasis had muchhigher expression of TGF β_1 than patients in T1-T2,stage Ⅰ-Ⅱ and without lymph node metastasis(P<0.05).Thepositive expression rate of VEGF(58.3%)in the TGF-β_1positive group is higher than that in the TGF-β_1 negativegroup(41.7%,P<0.05).Also,the microvessel count(54±18)in TGF-β_1,positive group is significantly higher thanthat in TGF-β_1 negative group(46±15,P<0.05).Themicrovessel count in tumors with both TGF-β_1 and VEGFpositive were the highest(58±20,36-140,P<0.05).Whereas that in tumors with both TGF-β_1 and VEGF negativewere the lowest(38±16,19-60,P<0.05).CONCLUSION:TGF β_1 might he associated with tumorprogression by madulating the angiogenesis in colorectalcancer and TGF β_1 may be used as a possible biomarker. AIM: Transforming growth factor (TGF) β_1 is involved in avariety of important cellular functions, including cell growththand differentiation, angiogenesis, immune function andextracellular matrix formation. Despite, the role of TGFβ_1 an ani angioganic factor in colorectal cancer is still unclear. WeC investigate the relationship between transforming growth factor β_1 and angiogenesis by analyzing the expression of transforming growth factor (TGF) β_1 in colorectal cancer, aswell as its association with VEGF and MVD. METHODS: The expression of TGF β_1, VEGF, as well as MVDwere detected in 98 colorectal cancer by immunohistochemical stain. The relationship between the TGF β_1 expression and VEGF expression, MVD was evaluated. Evaluation of the effect of TGF β_1 on the angiogenesis of colorectal cancers. RESULTS: Among 98 cases of colorectal cancer, 37 were positive for TGF β_1 (37.8%), 35 for VEGF (36.7%), respectively. The microvessel counts ranged from 19 to 139.8, with a mean of 48.7 (standard deviation, 21.8 ). Theexpressionof TGFβ_1was correlated significantly with thedepth of invasion, stage of disease, lymph nodemetastasis, VEGFexpression and MVD.Patients in T3-T4, stageⅢ-Ⅳ and with lymph node metastasis had muchhigher expression of TGFβ_1 than patients in The positive rate of VEGF (58.3%) in the TGF-β_1positive group was higher than that of the TGF-β_1 negativegroup (41.7%, P <0.05) 0.05) .Also, the microvessel count (54 ± 18) in TGF-β_1, positive group was significantly higher thanthat in TGF-β_1 negative group (46 ± 15, P <0.05) .microvessel count in tumors with both TGF- The VEGFpositive were the highest (58 ± 20,36-140, P <0.05) .Whereas that in tumors with both TGF-β_1 and VEGF negativewere the lowest (38 ± 16, 19-60, P <0.05) might he associated with tumorprogression by madulating the angiogenesis in colorectal cancer and TGF β_1 may be used as a possible biomarker.