In this paper, we simulate the effect of interaction between electrons on the electrical characteristic of silicon based single electron transistor (SET). The interaction between electrons is defined in the term of Coulomb blockade effect. These electrical characteristics involve conductance and I-V characteristic in SET structure. The simulation results show that when Coulomb blockade effect is included, the characteristic of I-V and conductance in SET shift to right. In addition, by reducing the quantum dot size, Coulomb blockade effect contributes greater effect. These results are shown in the characteristic of I-V and conductance which shift greater to the right in smaller quantum dot.