Spectral and monochromatic observations of two thin-filamentary nebulae S22 and YM29 have been carried out in the lines [O III] 5007A, [N II] 6584A and [S II] 6717+6732A. Radial stratification of the emission typical for photoionization excitation has been found: displacement between [O III] - bright regions and [S II] - and [N II] -bright regions is equal ΔR ∼ 0.1R (about 0.01 to 0.2 pc), the first ones being closer to the nuclei. Both nebulae are characterized by more diffuse morphology in the [O III] line and by thin-filamentary one in the [N II] and [S II] lines.