This paper focuses on the investment valuation of natural resource development projects under uncertainties of cash inflows，development costs and operating costs． On the basis of existing real option investment valuation models，with the management flexibilities of both postponing the investment decision and stopping the production in the production process considered，a real option valuation model on natural resource development projects with multiply uncertainties is established． An analytic solution of the model are also provided through applying the price principles such as exchange option and martingale process，and the main parameters are statically analyzed based on a real example of crude-oil development project in China．