With the aim to increase incoming solar intensity and decrease focus spot radius, a new type of solar surface cladding reactor with concentration quartz window is put forward in this paper. The comparisons of dimensionless heat flux distribution on working surface between the solar surface cladding reactor with concentration quartz window and the cladding reactor with plane quartz window are investigated by Monte Carlo ray tracing method. Besides, the impacts of refractivity and characteristic parameter of concentration quartz window on focus spot radius and peak solar intensity are also studied. (C) 2013 Elsevier Ltd. All rights reserved.