Optical performance is a significant factor for concentrating photovoltaic/thermal (PV/T) system, especially when the static concentrator is under outdoor condition, which would indicate the preliminary characteristics of the whole system. This paper put forward a novel static incorporated compound parabolic concentrator (CPC) with PV/T system, whose concentrator is composed of the mirror CPC and lens-walled structure, and can make full use of the total internal reflection and specular reflection. The theoretical model on the optical performance of the system under real application condition was established and the outdoor experiment was carried out to compare the simulation evaluation. The results illustrated that the difference on optical efficiency of the simulation and experimental outcome during the test is small, and maximum of it is only approximately 5%. The study obtained the optical efficiency model on the whole day of the static incorporated compound parabolic concentrator and verified the rationality of the design which provided the guarantee for the further research on the building integrated with concentrating photovoltaic/thermal (BICPV/T) system. (c) 2014 Elsevier Ltd. All rights reserved.