Abstract: We design and implement parallel level set evolution algorithm based on tensor product B-spline which improves accuracy and parallelism of level set evolution. Each step of evolution need compute B-spline coefficients. Furthermore, a parallel high approximation solver for diagonally dominant tridiagonal linear system based on exact LU decomposition is implemented, which is used to compute B-spline coefficients. Two step communications are used to remove communicating dependency, so as to communicate in parallel. As a result, it speeds up level set evolution efficiently.