A possibility for evaluation of pyrolysis kinetics of two Estonian shales and six biomass samples by Rock-Eval basic data is described. A pseudo-first-order kinetic model is proposed basing on S1, S2 and T-max determined only at one heating rate for calculating 1) the apparent activation energy (E) and frequency factor (A) for evolution of total hydrocarbons, 2) the current yields of hydrocarbons in time and temperature, 3) the kinetic constants (A(1) and E-1) for release of hydrocarbons from thermolabile ingredients. A linear relationship is revealed between kinetic constants of the samples studied: ln A(i) = - 4.455 + 0.228E(i), r = 0.9947, n = 8.