Factors influencing the pyrolysis of Yaojie oil shale, such as pyrolysis temperature, residence time, heating rate and particle size, were investigated. Pyrolysate yield was influenced most of all by pyrolysis temperature and residence time, followed by heating rate and particle size. Pyrolysis temperature and residence time had a great effect on the composition of retorting gas, while the influence of heating rate and particle size was less significant, corresponding to a change of oil yield of only 0.6% and 0.5%, respectively. The oil and gas yields were less affected when the oil shale sample was pressed into balls. The oil shale ball with a bentonite content of 6% was optimal.