The molecular formula of chloro-tenaciss igenin is C23H33O5Cl. The crystal belongs to monoclinic system. The space group is C22P21. The parameters of unit cell are a=15.782(7)?, 6 = 8.454(4)?, c = 8.074(4)? and β= 101.08(21)°. There are two molecules in an unit cell (Z = 2). Intensity data were collected on a PW-1100 four-circle diffractometer. The total number of independent diffractions amounts to 2097.The structure was solved by direct method (MULTAN 78). The refinement of the structure parameters was acheived by block-matrix least-square method, R=0.075. All the positions of hydrogen atoms were located by the difference Fourier syntheses and two of them, which are in the methyls, present disorder property.The chloro-tenaciss igenin molecule contained the conformation characteristic of tenaciss igenin. B-ring and C-ring, and C-ring and D-ring all exhibit cisforms obviously.