The 35Cl nuclear quadrupole resonance (NQR) spectra of CCI, in more than 20 clathrates have been measured in thc rangc 4-200 K. The crystal structures of CCI,/Dianin's compound (l), CCI,/Fe(AcAc), (3), CCI4/Ni(SCN),(3-MePy), (4), and CCI,/Ni(exar1)~(4,4'-dm-2,2'-bpy) (19) clathrates are also reported. Site symmetry and site multiplicity of the guest molecule in clathrates were determined by NQR spectroscopy and by X-ray crystallography. The degree of host-guest interaction was estimated from the NQR frequency shifts. The libration frequencies of the guest molecules in trigonal cavities were determined from NQR frequencies by Bayer-Kushida theory analysis.