In this paper, there is the case study which assesses the systems engineering capability maturity of the safety organization that performs the Railway Safety project using systems engineering method. To In ore effective and efficient a research and development to railway safety domain, a new research and development method can be progressively needed such as systems engineering. To assess quantitatively research of systems engineering efforts in the railway safety project, SECM(EIA/IS 731) Standard is utilized in the paper. It is by questionnaire that the capability maturity assessment is executed wit h the safety organization and staffs who performs the systems engineering activities; requirement analysis and management, interface control management. product verification and validation, and so on. As a result, the systems engineering capability level of the safety organization rises from 0 level at the initial project to 2 level after two years and all staffs give an affirmative answer about the importance and effectiveness of the systems engineering approach.