Communicating radius of automatic light trap surveillance network characterizes how well an area is monitored or tracked by automatic light traps. Connectivity is an important required that shows how nodes in an automatic BPH light trap surveillance network can eectively communicate. In this paper, we propose a new approach to determine the communication radius of an automatic light trap based on balltree structure. This approach will propose a parallel algorithm for implementing the balltree structure (CudaBalltree) and determining the communication radius of an automatic light trap by using CUDA NVIDA platform.