The EPR zero-field splitting parameters and structural distortion of Mn2+-doped (CH3)4NCdCl3 crystal in high-temperature phaseshave been studied by diagonalizing the complete energy matrices. The zero-field splitting parameters D and (aF) are demonstrated tobe negative and positive, respectively, and obtain a reasonable explanation together. Simultaneously, the distortion magnitude of locallattice structure around the Mn2+ ion in this crystal is determined, namely, DR=0.13A ˚ and Dh=2.975for T=124 K; DR =0.12A ˚ and Dh=2.610for T=297 K; DR=0.26A ˚ and Dh=2.870for T=573K. From the structural distortion, we deducethat a new structural phase transition should occur to the (CH3) 4NCdCl3 crystal at temperatures ranging from 297 to 573 K. This is alsoin agreement with recent differential scanning calorimetric measurements.