Abstract This paper, based on GTCF, examines the scope economy of domestic security companies with businesses devicifation between 2006 and 2011. The empirical results show that the labor inputs and physical capital inputs have great impact on the operating costs of the security companies in term of both increasing returns to scale and decreasing brokerage business output. The economies of scope are prevalent in the domestic security companies. While, the scope economy of the large security companies is greater than small and medium-sized security companies.