In this paper, we study the problem of network function deployment while user demands are served by both virtualized network functions (VNFs) and physical network functions (PNFs). A hybrid deployment scheme of VNFs and PNFs (HDVP) is proposed. A heuristic algorithm is developed for the HDVP scheme with the aim of minimizing the total cost of VNFs and PNFs. The results show the HDVP scheme achieves lower cost than the conventional only PNFs serving user demands scheme.