Abstract: The oblique detonation waves are simulated numerically to study the fine structures on the detonation surface, with Euler equations and the one step chemical reaction model. Two kinds of complicated structures are observed on the oblique detonation surface. One is composed of the transverse wave and triangle flame, which is special on the oblique detonation surface. The other is similar to the cellular structure on the normal detonation surface, but rarely observed on the detonation surface before. Simulation results demonstrate that they have similar mechanisms and can be converted into each other. Their formation and evolution processes are influenced by the inflow Mach numbers and the activation energy values.