For paraboloidal dish solar concentrators, the concentrating characteristics of concentrators with different apertures but the same area are investigated respectively with the same focal length and the same rim angle through the ray tracing. Considering several geometric factors including the influence of the sun shape, the shape of apertures, focal length and rim angle of paraboloidal dish, the shadow of receivers and so on, with the optical properties of concentrators, the geometric models for simulation are established, and the average flux distribution on the receivers is simulated and drawn with the software of TracePro. In order to make a quantitative evaluation for the concentrating performance of concentrators, the concept of efficiency factor of area is applied. The results of simulation show that when the area of apertures is same, the average flux distributions for the four concentrators with different shapes and identical focal length are similar. However, for those with different shapes but same rim angle, the average flux distributions have large attenuation except the concentrator with circular aperture. The solar concentrator of multiple panels with the same focal point is designed, and its concentrating performance is analyzed. The simulation results could present a useful reference for design and optimization of the solar paraboloidal dish concentrator.