Rodingite was discovered in the contact zone between amphibolite and serpentinitized ultramafic rock in mantle wedge of the upper subduction zone，Dongdegou，southwestern Tianshan Mountains. According to the degree of rodingitization，three rock types can be classified：amphibolite，rodingitized amphibolite and rodingite；corresponding mineral assemblies are：amphibole+andesine+quartz+titanite+apatite±salite；amphibole+anorthite+diopside+clinozoisite+chlorite±calcite；clinozoisite+ grossularite+diopside+ chlorite+calcite. Mineral chemistry and their major element characteristics of the rodingitic rocks show that metasomatic fluid is abundant in Ca and Al . Compared with the rodingitizition metasomatism occurred in ocean floor，the fluid contained in rodingitized rock here is much less intensive. Mass balance calculation also indicates that the convertion of amphibolite into rodingite is under the condition of enriched Ca and Al fluid. Further more, Mg adds into the rock in the early stage,but obviously decreases in the late stage during rodingitization.