The electron transport properties of a TaSi3 cluster sandwiched between two Al electrodes are investigated by using the first-principle-analysis. The results show that transport properties under low bias are determined by the 8th and 9th state of MPSH. Equilibrium conductance of TaSi3 cluster is very sensitive to the cluster-electrode distance. The oscillation form of conductance becomes obviously when the distance is greater than 0.35 nm. While the equilibrium conductance decreases quickly when the distance is less than 0.35 nm. The asymmetric current-voltage characteristics occur when the bias is in the range of -1 to 1 V and negative differential resistance is observed when the bias changes from 0.3 to 0.4 V.