Abstract: In order to investigate possible effects of environmental conditions on the mechanical properties of breakable capsules for cigarette filters, the weight, crushing strength, crushing deformation rate and elasticity index of breakable capsules were tested under different environments, and suitable environmental conditions for breakable capsule samples were proposed. The results indicated that:1) After adjusting for 48 h in the atmosphere of temperature (22±1)℃ and relative humidity (R.H., 60±2)%, the weights of capsules and filters with single capsule were constant. 2) The crushing strength, crushing deformation rate and elasticity index of breakable capsules were slightly different within 40%-60% R.H. and 10-40℃, and the degree of difference greatly correlated to the samples. The extreme temperature (lower than 10℃ or higher than 40℃) had a significant influence on the mechanical properties of the tested capsules, and the mechanical properties could not recover after a low temperature freezing. 3) There was no significant difference in the mechanical properties of breakable capsules under the temperature and humidity conditions in the production processes of breakable capsules, filter rods and cigarettes.