In this paper, we implement a vector potential integral equation method for electromagnetic scattering problems. The proposed equations are formulated by imposing both the tangential and normal components along the surface of a scatterer. They can be solved by a subspace projection method such as the Galerkin's or moment methods by considering the induced surface currents and the normal component n· A as unknowns. Numerical results validate the effectiveness, stability and accuracy of the proposed formulation. This work was supported in part by the Research Grants Council of Hong Kong (GRF 716112, 716713, 17207114), in part by the University Grants Council of Hong Kong (Contract No. AoE/P-04/08, 201211159076, 201209160031, 201311159188). W. C. Chew is funded by NSF CCF Award 1218552 and SRC Task 2347.001.