A trioctahedral chlorite/saponite ( 1:1) regularly interstratified clay mineral (C/Sap) is found in Lichuan area, Ensbi county, Hubei province. Occurring in calcic-sandy clay rocks and sandy petite of Triassic Badong Group, it has irregutar scaled, shape, with G=2.75, H=1-2, and n=1.558-1.572.Detailed chemical analysis, X-ray diffraction, infrared absorption, thermal analysis and electron microscopy all indicate that this mineral is made up of altexinate trioctahedral chlorite and trioctahedral saponite layers, haviltg d 060=1.531A，b0=9.19A，and cosinβ=29.05A.A good integral sequence of 001 diffraction obtained for the air dry sample suggests a regular intetstratification, with δ=0.1007,υc== 0.347。 The chemical structural formula is(Mgo.26Cao.18 K0.09 Na0.03 H0.10)0.66(Mg6.32Al1.56Fe3+0.48Fe2+0.15)8.51(Si6.47Al1.56)8O20(OH)10nH2O. C/Sap of Lichuan resemble correrisite in IR spectra, Its wave numbers of abs- onion are 3670, 3556, 3415, 1630, 1080, 1002, 953, 898, 665, 650, 520, 460 and 445 cm-1.On DTA curve there are four endothermic effects(118℃，235℃,600℃,820℃) and one exothermic effects (852℃) The total weight loss of C/Sap is 15.9%,of which dehydroxylation weinht loss is 8.37%.