Camellia oleifera fruit shell (COFS) and Camellia oleifera seed shell (COSS) are agricultural residues in the tea-oil processing, and rich in lignin. Analyzing the characteristics of the milling wood lignin from COFS (COFS-MWL) and COSS (COSS-MWL) was a fundamental step in achieving efficient application of the shells. The analysis showed that COFS-MWL was a kind of G/S type lignin, while COSS-MWL contained catechyl lignin (C-lignin) coexisting with G/S type lignin. This means that COSS was expected to become an important source of C- lignin. In addition, activation energies of COFS-MWL and COSS-MWL pyrolysis reaction were calculated based on Flynn-Wall-Ozawa and Kissinger-Akahira-Sunose model. The mean values obtained from two methods were similar about 174 kJ/mol and 268 kJ/mol, respectively. The main thermal degradation products of COSS-MWL were catechols at the pyrolytic temperature of 700 °C. The result confirmed again that COSS-MWL had rich unique C-lignin structure. In general, this study will be of great significance for the production of catechol compounds from biomass and the high value-added development of agricultural residues.