Halo-olefinic impurities in 1,1,1,3,3-pentafluoropropane (HFC-245fa) product used as blowing agents, etc. could damage the human body and must be removed. Activated carbon was treated by HCl, HNO 3 and NaOH, respectively. The adsorptive performance of unmodified and modified activated carbons for the removal of a low content of 1-chloro-3,3,3-trifluoro-1-propene (HCFC-1233zd), 1,3,3,3-tetrafluoro-1-propene (HFC-1234ze), 1-chloro-1,3,3,3-tetrafluoro-1-propene (HFC-1224zb) and 2-chloro-1,3,3,3-tetrafluoro-1-propene (HFC-1224xe) halo-olefins in the 1,1,1,3,3-pentafluoropropane (HFC-245fa) product was investigated. These halo-olefinic impurities could be substantially removed from the HFC-245fa product via the adsorption over activated carbon when the adsorption temperature was under 333K, which can be attributed to the π–π dispersion interactions between the halo-olefins and carbon graphite layer. The basic surface groups of activated carbon could catalyze the decomposition of HFC-245fa to form HFC-1234ze. However, the significant increase in the amount of surface acidic groups of activated carbon led to a distinct decrease of adsorption capacity due to the reduction in the micropore volume of adsorbent and a decrease in the strength of the π–π dispersive interactions between halo-olefin molecules and carbon basal. The breakthrough time of halo-olefinic impurities on activated carbon increased with the increase of molecular mass and the decrease of molecular symmetry.