This paper presents a general method for parametric trimmed surface development. Parametric trimmed surface development is primarily used for flattening a 3D surface into a corresponding 2D pattern or surface. This method can be applied in computer aided design, texture mapping, ship building, etc. First, the surface is triangulated and mapped onto a plane. This initial planar mapping has the same topology as its original surface. Then, a spring-mass system is applied to deform the plane. The surface elastic deformation energy distribution is indicated by a color graph, which determines a surface cutting line. The method presented here can efficiently solve development problems for complex trimmed surfaces. Accuracy of a developed surface can easily be controlled locally. Thus, compared to earlier methods, this method provides more flexibility for solving CAD and CAM surfacing problems.