The work aims to control local growth of film on sample surface by changing inter-electrode distance. Inhomogeneous electric field was created by changing the cathode area. Micro-arc oxidation tests were conducted respectively. In accordance with time-voltage cruve, arc discharge, distribution of film thickness, etc., effects of inter-electrode distance on micorarc induction and growth process of 6061 aluminum alloy in inhomogeneous field were analyzed. In inhomogeneous field, final voltage firstly decreased to 450 V from 550 V when inter-electrode distance increased from 2 mm to 50 mm, then it gradually increased to 650 V; micro-arc induction time increased from 10 s to 310 s and then decreased to 90 s; film thickness in central area decreased to 1.5 μm from 7.5 μm and then increased to 4 μm while that in marginal area slowly increased to 4 μm from 0 μm. In case of small inter-electrode distance of micro-arc oxidation, increase of inter-electrode distance might reduce reaction rate and improve film homogeneity. Inter-electrode distance can have significant effects on the growth speed, thickness and morphology of the film. Growth region can be controlled by adjusting appropriate inter-electrode distance to realize local preferential growth of the film