On the basis of the newly published clinopyroxene-melt equilibrium thermobarometer, the authors calculated the clinopyroxene-melt equilibium temperature and pressure of mantle xenoliths_bearing basalts at Kuandian, Hannuoba and Mingxi in eastern China. The res_ ults show that the crystallization temperature and pressure of cpx porphyritic crystals in alkali basalts are generally higher than those in subalkali basalts, and the crystallization temperature and pressure of cpx megacrysts are higher than those of phenocrysts, which further proves that the cpx megacrysts crystallize at higher pressure than cpx porphyritic crystals. The existence of cpx phenocrysts at various pressures indicates that the cpx can crystallize continually along the way through which the magma moves upward. Regression analysis shows that although the basalts which bear mantle xenoliths move up so fast, they are not adiabatic but have heat diffusion. The comparison of temperatures and pressures between the crystallization of cpx phenocrysts (or megacrysts) and that of xenolith in alkali basalts indicates that host magma exists originally deeper than the mantle xenoliths in terms of pressure and so the xenoliths are fragments of the upper mantle captured by magma along the ascending way instead of being the source residues of host magma as considered previously.