The ³⁵Cl nuclear quadrupole resonance (NQR) spectra of CCI₄ in more than 20 clathrates have been measured in the range 4-200 K. The crystal structures of CCI₄/Dianin's compound (l), CCI₄/Fe(AcAc)₃ (3), CCI₄/Ni(SCN)₂(3-MePy)₄ (4), and CCI₄/Ni(exan)₂(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.