The shape and aggregation of particle have a strong influence on the light scattering property. The diffusion-limited aggregation model (DLA) of fractal growth is used to simulate the possible structures of aggregates, and the fractal dimension of aggregates is calculated with the method of gyration radius. The light scattering property of nano-graphite aggregates is studied on the basis of discrete dipole approximation (DDA) method. For aggregates with different numbers of primary particles and with different fractal structures, numerical results of the scattering intensity and the degree of linear polarization to different incident wavelengths are illustrated. The results show that the light scattering properties of nano-graphite aggregates are related to incident wavelength, particle numbers and fractal dimension, and are different from those of the equal volume sphere.