Due to the expected importance of unconventional oil in China's domestic oil supply, this paper first investigates the four types of China's unconventional oil resources comprehensively: heavy and extra-heavy oil, oil sands, broad tight oil and kerogen oil. Our results show that OIP (Oil-in-Place) of these four types of resources amount to 19.64 Gt, 5.97 Gt, 25.74 Gt and 47.64 Gt respectively, while TRRs (technically recoverable resources) amount to 2.24 Gt, 2.26 Gt, 6.95 Gt and 11.98 Gt respectively. Next, the Geologic Resources Supply-Demand Model is used to quantitatively project the long-term production of unconventional oil under two resource scenarios (TRR scenario and Proved Reserve + Cumulative Production scenario). Our results indicate that total unconventional oil production will peak in 2068 at 0.351 Gt in TRR scenario, whereas peak year and peak production of PR (proved reserves) + CP (Cumulative Production) scenario are 2023 and 0.048 Gt, significantly earlier and lower than those of TRR scenario. The implications of this growth in production of unconventional oil for China are also analyzed. The results show that if the TRR scenario can be achieved, it will increase total supply and improve oil security considerably. However, achieving the production in TRR scenario has many challenges, and even if it is achieved, China will still need to rely on imported oil. (C) 2014 Elsevier Ltd. All rights reserved.