This paper demonstrates the result of Safety Integrity Level (SIL) allocation for Honam KTX Train Control System (TCS), by applying the semi-quantitative approach. TCS is defined in this paper as the set of TVM SEI, Supplementary Safety Equipment, Power Equipment, TCS Integrated Maintenance System (TIMS), and Local Control Panel (LCP). SIL allocation is performed for these constituent subsystems of TCS. Three approaches for SIL allocation being widely used in railway application are compared in terms of the conservativeness of the allocation result; qualitative, quantitative, and semi-quantitative methods. The semi-quantitative method, based on the risk matrix and the relationship between Tolerable Hazard Rate (THR) and SIL, is less pessimistic than the qualitative method, but more conservative than the quantitative method, in the sense that it utilizes more information (e.g., risk reduction factors involved in the hazard occurrence) than the qualitative method which purely depends on the configuration of Risk Graph. Based on three principles of the semi-quantitative method, the SIL allocation process is performed for the subsystems composing TCS.