Organic Rankine cycle (ORC) is a promising way for low temperature waste heat utilization. The performance of an ORC system is strongly related to the working fluid. Therefore, working fluid selection is a primary task in customizing an ORC to a specific background process for waste heat recovery. In refineries, there are huge amounts of waste heat, in which some waste heat streams simultaneously release latent heat and sensible heat, and the target temperature is constrained in most cases. This paper focuses on the working fluid selection of the ORC recovering different types of waste heat in refineries. In this paper, the waste heat sources in refineries are classified into three types (i.e., sensible heat source, combined heat source, and latent heat source) according to their characteristics. The impacts of waste heat sources characteristics (i.e., waste heat type, inlet and target temperatures of waste heat, the ratio of latent to sensible heat) on the working fluid selection are investigated. The results show that the characteristics of waste heat exert great influence on working fluid selection. Different types of waste heat source present different thermodynamic criteria for optimum working fluids. The inlet temperature (T-m) and target temperature (T-tar) of waste heat, and the ratio of latent to sensible heat (R) of waste heat source have influence on the selection of working fluid. However, the degree of influence depends on the waste heat types. Thermodynamic criteria on working fluid selection for each type of waste heat sources are drawn in this paper.