Soil pore systems under no tillage (NT) and moldboard tillage (MT) in the black soil zone of Northeast China were extracted from soil thin sections with digital image process techniques and the multifractal characteristics of soil pore structure were studied with method of moment. Results indicate that NT decreased the macroporosity (>500 m) in〖LM〗 the surface layer (0~5 cm)，but increased the total porosity and macroporosity at 10~15 and 20~25 cm depth. Multifractal characteristics were observed at 64~1 024 pixel scales and generalized dimensions (D_q)，multifractal spectral (f (α)) and other related parameters reflected characteristics of the pore structure in the soil sections under NT and MT. The multifractal spectra of the pores in the surface layer apparently leaned toward the right side but approached to symmetry with increasing depth. Compared to MT，NT increased the Δα（α_-10-α₁₀） and ΔD (D_-10-D₁₀) of soil pore structure，and complexity of soil pore system，especially at 10~15 cm and 20~25 cm in depth.