In a tubular reactor ，the catalytic properties of biomass char and dolomite in tar catalytic cracking were studied. Quartz sand was also tested for comparison. Through the comparisons of tar conversion rate, pyrolysis products, pyrolysis gas composition and kinetic parameters, it can be known that biomass char as the catalyst of tar gives the highest tar conversion rate, the largest share of gas in pyrolysis products, the more proportion of combustible gas in pyrolysis gas and the lowest kinetic parameters among three materials used in the study. The catalytic properties of biomass char are significantly higher than that of quartz sand and slightly better than dolomite, so it is an efficient catalyst for tar cracking.