The behavior of the pyrolysis and the kinetics of the spiny retamo (Ulex eurioaeus L.), problematic plant in the eastern slope in Bogotá Colombia, has been studied in a thermobalance, as a previous step for its valorization by pyrolysis in order to obtain fuels and chemical products. The kinetic model consists of a multicomponent mechanism that describes the formation of volatiles that involves three parallel and independent reaction networks that correspond to the decomposition of the three main pseudo-components of the biomass: hemicellulose, cellulose and lignin. Similarly, other products are considered as fixed coal and ashes produced. The thermogravimetric curves and the kinetic parameters have been compared with those obtained for other materials, and the chemical characteristics of the biomass have been determined. Although the samples are highly heterogeneous due to their composition, the degradation of these is similar to that of other lignocellulosic materials, which shows that their valorization pyrolysis is feasible.