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We present results of the electronic band structure, Fermi surface and electron transport properties calculations in the orthorhombic n-and p-type SnSe, applying the Korringa-Kohn-Rostoker method and the Boltzmann transport approach. The analysis accounted for the temperature effect on crystallographic parameters in P nma structure as well as the phase transition to CmCm structure at Tc ∼ 807 K. Remarkable modifications of the conduction and valence bands were notified upon varying crystallographic parameters within the structure before Tc, while the phase transition mostly leads to the jump in the band gap value. The diagonal components of the kinetic parameter tensors (velocity, effective mass) and resulting transport quantity tensors (electrical conductivity σ, thermopower S and power factor PF) were computed in a wide range of temperature (15 − 900 K), and hole (p−type) and electron (n−type) concentrations (10 17 − 10 21 cm −3 ). SnSe is shown to have a strong anisotropy of the electron transport properties for both types of charge conductivity, as expected for the layered structure, with the generally heavier p-type effective masses, comparing to n-type ones. Interestingly, p-type SnSe has strongly non-parabolic dispersion relations, with the 'pudding-mold'-like shape of the highest valence band. The analysis of σ, S and PF tensors indicates, that the inter-layer electron transport is beneficial for thermoelectric performance in ntype SnSe, while this direction is blocked in p-type SnSe, where in-plane transport is preferred. Our results predict, that the n-type SnSe is potentially even better thermoelectric material than the ptype one. Theoretical results are compared with the single crystal p-SnSe measurements, and a good agreement is found below 600 K. The discrepancy between the computational and experimental data, appearing at higher temperatures, can be explained assuming an increase of the hole concentration vs. T , which is correlated with the experimental Hall data. arXiv:1502.04599v3 [cond-mat.mtrl-sci]