The fractal dimension and percolative structure of Li-inserted BaTiO3 films were studied by the methods of cyclic voltammetry, impedance spectroscopy and window box scaling applied to electron micrographs of the film. All three methods give a fractal dimension of approximately 2.32. Analysis based on percolation theory revealed a fractal dimension of 2.52 at the percolation threshold, where transition to the conductive structure occurs. Comparing the two values, it is concluded that lithium insertion in BaTiO3 creates a poorly conductive fractal structure in the bulk of the film. In this work, the length scale for measuring the roughness of the film appears smaller than the correlation length derived on the basis of the percolation criteria and confirms the above conclusion.