Abstract: For controlling the temperature in cigarette filter, an eicosane/expanded graphite (EI/EG) composite phase change material was prepared with capillary adsorption method, wherein eicosane was used as phase change material and graphite as carrier material. The prepared material was added into cigarette filter, the effect of its addition on temperature distribution in cigarette filter was investigated during smoking. The physical-chemical structure and thermal properties of the composite phase change material were characterized by DSC, thermal conductivity coefficient detector, SEM, XRD, FT-IR, and nitrogen adsorption-desorption. The temperature distribution in filter was detected by the cigarette combustion temperature detection system and characterized with temperature distribution in the temperature field and mean volumetric temperature. The results showed that:1) At the content of 92% (mass concentration), eicosane in expanded graphite approached to adsorptive saturation with the phase transition temperature of 40.2℃, phase change enthalpy was of 162.9 J/g, and the thermal conductivity of 1.304 W/(m·K); the prepared eicosane/expansion graphite material had high latent heat and excellent thermal conductivity. 2) In the prepared material, eicosane was physically composited with expanded graphite, the attribute of basic material kept unchanged. 3) When adding 40 mg of 92% EI/EG phase change material into a cigarette filter, the temperature in filter decreased to below 30℃ during smoking under ISO regime, the temperature distribution in filter was uniform, it indicated that the temperature in filter was effectively controlled by the material.