Abstract: Abstract: With the consumption of fossil fuels, it would be more and more difficult to depend on fossil fuels for energy, which together with the environment problems forces people to find a clean and renewable alternative energy. Because of the huge amount, the environmental friendly and renewable features, the biomass has aroused considerable attention. Bio-oil is one of the products from biomass pyrolysis. As a kind of promising alternative energy, bio-oil has showed some good characteristics of high energy density, convenient storage and transportation. In generally, bio-oil is brown acid liquid with smoke and irrigating smell. The major components of bio-oil are acids, phenols, and hydrocarbon and so on. Based on the different component characteristics, bio-oil could be divided into two parts：the light part which is called pyroligneous, and the heavy part. The heavy part consists of large molecules from the procedure of pyrolysis, which is difficult to use for its high viscosity and high oxygen content. Catalytic cracking is one of the useful methods for bio-oil upgrading, although the lifetime of the catalyst is influenced by the char deposit. More and more promising materials are used for catalyst cracking, however, the absence of theoretical support makes the upgrading process blind. In this paper, pine-nut shell was pyrolyzed through continuous pyrolysis device. In order to gain more liquid product, the reaction parameters of temperature (350-650℃) and time (2-8 min) were researched. The GC-MS was used to analyze the major constituent of the pine-nut shell bio-oil produced at the suitable situation, as well as its properties including viscosity, heat value, water content and pH. The heavy part of bio-oil was divided from the bio-oil for the upgrading experiment. The catalytic cracking experiment was carried out on the fixed bed reactor. In the experiment HZSM-5 and NiO/HZSM-5 zeolite were used to catalyze the heavy oil respectively. The heavy oil was compared with the catalyzed one on the composition and properties. The results showed that in the range of 350-650℃, the yield of bio-oil had a trend that increased initially and decreased afterwards as the increase of temperature. In the range of 2-8 min, the yield of bio-oil had a similar trend with time passing. Besides the influence on bio-oil yield, the results also indicated the suitable temperature and time was 450℃ and 6 min, respectively, at which the yield could be 40.74%. The GC-MS result showed that the major constituent of pine-nut bio-oil was phenol, some acids and arena. The upgrading experiment also proved that the heavy component was decreased by 10%, the viscosity was decreased to 400 mPa·s and the heat value was increased by 13%-16% by the catalysis upgrading of the HZSM-5 and NiO/HZSM-5 zeolite. The combustion stability of the upgrading oil was improved as well. Although the catalysis result was good, the deposit of char still existed, and the addition of NiO improved the resistance ability of the catalyst to carbon deposition. All of the above results provided a theoretical basis for experimental study of upgrading bio-oil.