Multiple ellipsoid model is applied to the 4He,10He-18Na2,23Na2, and 37Na2collision systems, and integral cross-sections for rotational excitation and the total collision cross-sections at the incident energy of 50,100 and 200 meV are calculated. By analyzing the differences of these integral cross-sections, the change rules of the integral cross sections with the increase of rotational angular quantum number of Na2 molecule, as well as with the change of the reduced mass of symmetric isotopic substituted system are obtained. Based on the calculation, influence on the cross-sections exerted by the variations in the reduced mass of systems and in the relative incoming energy of incident atom is discussed. Moreover, at the relative incident energy of 100 meV, the contributions of different regions of the potential to integral cross-sections of rotational excitation for10He-18Na2,23Na2 and 37Na2 collision systems are investigated.