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The radiation emission spectra of polarized photons emitted from charged particles in single oriented crystals are obtained in Bayer-Katkov quasiclassical approach. The results of numerical calculations are presented in the region of small angles of incidence for which the coherent theory fails but magnetic bremsstrahlung region isn't yet achieved. The spectral distribution of linear polarization degree repeats, in general, the form of the intensity distribution. At sufficiently small angles, in the case of planar orientation of crystal, there is a wide maximum of essential linear polarization at low frequencies ω/ε = 0.1 − 0.3.The processes of photon emission from charged particles and e − e + pair creation by photon at high energies in oriented single crystals are widely applied in experimental physics for the production of polarized photon beams, as well as for the analyses of photon polarization. For sufficiently large incident angles ϑ 0 to crystal axis/planes ϑ 0 ≫ ϑ v , where ϑ v is the characteristic angle given by ϑ v = U 0 /m (U 0 is the scale of axial/planar potential and m the electron mass) these processes are well described in the theory of coherent bremsstrahlung (CB) and pair production (CPP) [1]. This theory is constructed in the framework of the first Born approximation in crystal potential and fails at small angles and very high energies, where these processes become of magnetic bremsstrahlung nature.Recently V.N. Bayer with co-authors developed a general theory for radiation emission from high-energy particles and pair production by high-energy photons in strong crystalline fields [2]. This theory is not restricted by the first Born approximation and is based on the quasiclassical character of motion of ultrarelativistic particles in strong fields. For ϑ 0 ≫ ϑ v , this theory is reduced to the standard theory for CB and CPP. At very small angles ϑ 0 ≪ ϑ v , the quasiclassical theory reproduces the results of constant field approximation (CFA). For intermediate angles, ϑ 0 ∼ ϑ v , the numerical calculations in the exact theory face serious mathematical difficulties and to obtain specific numerical results some approximation and modeling methods have been developed. First numerical results of the radiation emission spectra in the quasiclassical theory were published in [3] (in the framework of additional modeling assumption); exact calculations were presented in [4]. In Ref.[5] an analytical method of calculations in the framework of quasiclassical approach was developed and new numerical results were presented. These papers demonstrate an essential difference of exact spectra from the corresponding results of coherent theory at small angles ϑ 0 ≤ ϑ v . There is good agreement between first experimental results at small angles [6,7] and these calculations.Polarization characteristics of radiation emission in single crystals in the region of applicability of CB are well investigated in experiments (at the energies of incident electrons up to