Transport properties have been investigated for the epitaxial superconducting NbN thin films. We analysed the excess conductance σ' ≡ σ(T) - σ~N by the sum of the Aslamazov-Larkin (AL) and Maki-Thompson (MT) terms for thermal fluctuations above T_c, where the σ~N ≡1/(R_(sq))~N is the normal state sheet conductance. We have found that the theoretical expression σ'_(theo) (T) = σ'_(AL) (T) + σ'_(MT) (T,δ) can be well fitted to σ'_(exp) (T) with use of the suitable value of the pair breaking parameter δ in the MT term relating to the inelastic scattering rate 1/τ_(in)(T) as δ = πh/8k_B Tτ_(in). The rate 1/τ_(in)(T) given by the sum of 1/τ_(fluc)(T), 1/τ_(e-e)(T) and 1/τ_(e-ph) (T) is determined from the analysis of the magneto-conductance Δσ = σ(H) - σ(0) by the sum of AL, MT and the localization terms, where the first, second and third terms correspond to the rate due to the superconducting fluctuation effect, electron-electron and electron-phonon interactions, respectively. The (R_(sq))~N dependence of δ is expressed by δ = δ_0 + (αR_(sq)~N), where the first term δ_0 due to 1/τ_(e-ph) (T) and the second term due to the sum of 1/τ_(fluc)(T) and 1/τ_(e-e)(T). Although we obtained a reasonable value of Debye temperature Θ_D ≈630 K from the δ_0, the magnitude of the α is about 5 times larger than the theoretical value.
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