The effect of disorder on transmission spectra of two-dimensional photonic crystals with transfer matrix method(TMM) was investigated.Specifically,the effects of disorders of lattice structure,radius of cylinders,shape of cylinders,and the dielectric constant on the transmission spectra of a two-dimensional square lattice crystal with frequency were studied by using the RAND function in Fortran,respectively.The numerical simulation results show that,in the case of weak disorder,the effect of the shape of cylinders is the most significant while the effect of radius of cylinders is the weakest. The characteristics of transmission can be well maintained if the disorders are limited within a certain range.In the case of strong disorder,a common phenomena found in different disorders is the localization of photons at low frequencies.The width and position of the band gap are affected by the strong disorder.In addition,a number of resonant modes are found in the transmission.