To study the wind field characteristics of valley and col terrain and speedup effects in typical positions, Computational Fluid Dynamics (CFD) simulation methodology was employed. The results of an isolated hill obtained from CFD simulations, wind tunnel tests and codes were compared to validate the results of CFD simulation. Valley and col terrain were conducted by CFD. The speedup effects in typical positions of valley and col terrain were analyzed and some design suggestions were given for the top of hill and the inner side of hill bottom. The results show that the speedup effect on the top of hill is the most significant. The speedup effects on the cross-wind plane of an isolated hill are more significant than those on the along-wind plane. The results of CFD simulation match well with those obtained from wind tunnel test. The speedup effect on the top of col is more significant than those on valley and isolated hill. The speedup ratio at the inner side of hill bottom becomes greater with the decreasing distance between two hills. At the inner side of hill bottom under two adjacent hills condition, wind speedup ratio is less than the lower limit of the code for valley terrain and larger than the upper limit of that for col terrain when the distance between two hills is less than half diameter of hill bottom and the height above the hill is less than forty percent of hill height. The speedup effects on the top of hill are almost unchanged under various hill distance conditions. It is not commended to choose cols and tops of hills as the construction sites.