A calibration method for three-dimensional sensing scheme based on phase mapping is described. The calibration procedure is based on the definition of a unique coordinate system in the structure system,and thus,a constraint is introduced between two devices. Fringe projection and phase mapping are used to convert the phase map to world coordinates of the object surface by a matbematieal model. Using the model,the 3-D coordinates of range image can be obtained with moderate accuracy,which will be compared with the prescribed benchmark in order to build up a square-error based objective function, leading to a non-linear equation. A two-step procedure is developed to solve the equation, and all structural parameters involved in 3-D sensing system can be detemained with appropriate accuracies. Experimental results show that these proposed approaches are accurate and robust.