Permeation of n-alkanes through cis-1,4-polybutadine crosslinked using conventional, efficient, and peroxide vulcanizing systems was studied by a gravimetric method. Four alkanes from n-hexane to n-nonane were used. In n-octane, the studies were conducted in the temperature range of 27-70 degreesC.The sorption data was used to estimate the diffusion and permeability coefficients, the activation energy for diffusion and permeation, the entropy and enthalpy of sorption, polymer-solvent interaction parameter, and the degree of crosslinking. The various parameters estimated indicate that permeability of the membranes depends more on the degree of crosslinking than on the nature of crosslinks. Increase in permeant chain length was found to lower permeability.