Light scattering by particles is an important part of optical test. The T-matrix method is widely used for the computations of light scattering by particles. The most prevalent way to calculating T-matrix is the extended boundarv condition method （EBCM）, which, however, is largely limited to axisymmetric and near-spherical particles. A new method for calculating the T-matrix is presented. It integrates directly on the particle surface and converts the integral to the summation by meshing the surface with a series of triangles. This method enables us to calculate light scattering by non-axisymmetric and even more realistically shaped particles