Thermochemical conversion is the key technology for the comprehensive utilization of Chinese oil shale resources. Oil shales from three mining areas of Huadian Jilin were pyrolyzed at 500 ℃ in a quartz tube reactor and their pyrolyzed cokes and shale oil were derived. One oil shale was also pyrolyzed at 600 ℃ and 700 ℃ to assess the influence of temperature on pyrolysates. FTIR analysis was carried out to study the raw shales and their products. The results showed that shale oil had similar functional groups as the organic matter of oil shale, mainly aliphatic hydrocarbon, and the shale oil contained more of it than the raw material. The shale with more aliphatic oil yielded more oil. That with less aliphatic and more aromatic one yields less oil, and its coke is rich in condensed aromatics. Pyrolysis was almost completed at 500 ℃. Oil yield did not increase further with temperature, but secondary pyrolysis strengthened. At 700 ℃ carbonates began to decompose.