In this study, in order to replace the conventional steel bogie with a composite bogie, a composite side beam made of glass/epoxy was developed to be used in the bogie frame of an urban subway train. The composite side beam was manufactured using two different manufacturing method; autoclave curing method and resin transfer moulding method (RTM). And, then, they were tested under a vertical load of 140 kN to evaluate the structural behavior. Moreover, the stress and strain distribution was evaluated with the finite element method and compared with the experiment. The maximum deflections of the two side beam were 7.74 mm and 8.25 mm, respectively. The side beam made by RTM appeared a little softer than the autoclave cured one due to the lower fiber volume fraction. Through the parametric study for the different design parameters, it was known that the variation of the side beam height appeared to be strongest effect to deflection.