Software outsourcing has became a common method used in software development. To guide the software outsourcing process pattern decision, this paper puts up a neural network based decision model which is made up of a group of orthogonal and concurrent input factors, a three-tier neural network decision architecture and a group of output process patterns. The model is verified with a real software outsourcing process pattern decision case. This model provides the theory for the development of outsourcing decision tools and complete decision supporting mechanism for various outsourcing model in every phase of software engineering.