Abstract: This study investigates the structural performance of Polymer Matrix Composite infills (PMC infills) under diagonal compression load by means of numerical analysis with consideration of three important parameters. The three parameters considered in this study are variation of temperature, length of contact and type of support at the connection between infill and frames. These three parameters can greatly affect the performance of the infill panel. Results shown that the strength of PMC panels decreases as the temperature increases, this is due to the polymeric behaviour of fiber-reinforced polymer in the panel. Moreover, when the contact length increases, the strength of panel shows a converging trend. This result could assist in the decision of support type for the FE model.