Abstract:The skarns in the Xujiachong from Jingshan county, Hubei Province, are virtually the products of dolomitic xenoliths suffered contact-thermal metamor- phism and contact metasomatism, and may be divided mainly into two types; monticellite-andradite-diopside skarn with porphyroblastic texture in the outer zone of xenolith and andradite-diopside skarn with fine grained granoblastic texture in its inner. Their mineFal assemblages are shown as following, diopside, andradite monticeJlite, biotite, perovskite, ilmenite and titanite in outer zone of xenolith and diopside, andradite, biotite, rutile, magnetite, apatite and zircon in its inner zone. The rock-forming minerals of andradite-diopside skarns are mainly diopside, andradite, monticellite and biotite, whereas the accessory minerals consist of perovskite, ilmenite, ruble, titanite, magnetite, apatite and zircon. The monticellites were suffered intense serpentinization (always occurs as pseudomorphs after olivine),and sometimes altered to vesuvianite, occuring as poaphyroblastics in the outer zone of xenolith. The andradites are the most common in these rocks, which occur not only as porphyroblastics, but also as fine grains纽the matrix. Their structural formula is shown below; (Ca2.755 Mg0.20. Fe2+0.035)3.00(Fe3+1.85, Ti0.05, A10.01)2.00(Si2.916, Al0.074)2.99O12.00 The crytallization history and the temperature conditions for formation of the andradite-diopside skarns are discussed by the authors in this paper, and according to Evans and Trommsdorff (1980),using the H. G. F. Winkles method (1975),the equilibium temperatures for coexisting of monticellite and andra- Bite pair in the skarns are calcutaled at 680-700℃.