A study on the analysis of hydrocarbon class composition was carried out by thin layer chromatography with flame ionization detection(TLC/FID). The optimum analytical conditions, experimental reproduction, standard deviation, quantitative correction factors of hydrocarbon class and so on were investigated. The instrument used were Mark III, LATROSCAN TH-10 analyzer, thin layer rod was a CHROMAROD silica rod(150 mm x 0.9 mm i.d). A satisfactory TLC/FID analytical method was established after a series of experiments and investigation. Typical heavy oils from coal were investigated based on this method. The optimum conditions were that the flame ionization detector was operated at a hydrogen flow rate of 100 mL/min corresponding to 90 kPa and air flow rate of 1.9 L/min. The determinations in groups of saturated hydrocarbons, aromatics, resins and asphaltenes were performed by using n-heptane, toluene and V(chloroform):V(methanol) = 95:5 as developing solvents. The developing distances were controlled at 10 cm, 5.5 cm and 2.5 cm respectively. In the present paper qualitative and quantitative analysis have been studied. And the method established was sufficiently applied to determine heavy oils from coal of coking plants of Shanxi.