中文摘要：

Major element, REE and oxygen isotopic com-positions of fourteen clinopyroxene megacrysts from Nushan, eastern China have been obtained. They are believed to rep-resent crystallization products of one mantle-derived alkali basaltic magma. Oxygen isotopic ratios are homogeneous within the same sample, but heterogeneous among different samples, δ18O values of these megacrysts are from 4.86‰ to 6.48‰. We suggest that the oxygen isotopic variation of cli-nopyroxene megacrysts should be inherited from their source magma, and the heterogeneity of source magma re-sults from contamination of subducted oceanic materials.