Abstract: The thermal decomposition of a kind of brominted epoxy resin(BER) printed circuit boards was investigated by using TGFTIR and PyGC/MS. The mechanism of the thermal decomposition of the resin was discussed. The experimental results show that during the thermal decomposition of BER, the brominated parts are firstly decomposed with the splitting of OH—C, O—CH2, C—C (Benzene) bonds, and the pyrolysis products such as CO, acetone, bromomethane, bromophenol and 2,6-dibromophenol are produced. The decomposition of unbrominated parts is conducted at higher temperature with the splitting of OH—C， CH2—O—benzene, C—C(Benzene) bonds, and the pyrolysis products containing phenol, p-isopropylphenol, p-isopropenylacetylphenol, o-ethylphenol and p-methylphenol are made.