Fractal dimension has been applied to study the interface of nanostructured AT13 coatings deposited by micro-plasma spraying. The result shows that the higher the spraying current, the greater the fractal dimension and adhesive strength. Fractal dimension and adhesive strength increase firstly and then decrease with increase of Ar flow rate. Fractal dimension can be used to characterize adhesive strength of the coatings. Adhesive strength increases with rising of fractal dimension. There is a proximate linear relationship between the logarithm of adhesive strength and fractal dimension: ln(σ)=176D-262.