为探讨有耗色散媒质光子晶体的特性，引入一种计算有耗色散光子晶体能带结构的方法，基于有限元法将能带结构的计算简化为求解关于Block波矢的二次特征值问题，可以有效地得到色散材料光子晶体的能带结构和特征模.分析了三角晶格介质光子晶体能带结构并与现有方法对比，结果表明两种方法在TM模和TE模下得到的能带结构完全相同，验证了该方法的有效性.分析了无耗及有耗色散光子晶体的能带结构,发现无耗光子晶体场强集中于色散媒质与空气的接触面，并呈现出明显的表面等离激元特性，具有对称性，而有耗光子晶体场强减小，表面等离激元变弱,对称性被破坏.相关结果可为有耗色散光子晶体以及表面等离激元的研究提供参考.

In order to explore the properties of photoniccrystals, the finite element method was introduced to calculate the band structure of lossy and dispersive photonic crystals with triangular lattice. By using this method, the calculation of band structure is reduced to a quadratic eigenvalue problem which the eigenvalue is the Bloch wave vector, the band structure and eigenmode can be obtained more effectively. The band structure in the TE and TM mode of photonic crystals with dielectric material in triangular lattice was compared with the reference to demonstrate the accuracy of the method. Furthermore, the dispersion relation of the lossy and lossless photonic crystals was also given by the proposed method. The symmetry and surface plasmon polarizations properties are found in lossless photonic crystals and electric field distributions are concentrated on the interface of dispersive materials and air. It is demonstrated in the lossy photonic crystals that the symmetry is destroyed, the surface plasmon polarizations properties are weakened and electric field density is decreased. The results can be used as theoretical basis and reference for studying the lossy photonic crystals and surface plasmon polarizations.