We have experimentally observed anomalous spreading of aqueous alcohol solutions on flat and rough fractal agar gel surfaces. On flat agar gel surfaces, extremely fast spreading [theta(D)(t) proportional to t(-0.92)] that differs from Tanner's law [theta(D)(t) proportional to t(-0.3)] was observed when the liquid contained over 9 wt % of 1-propanol in which strong Marangoni flow was observed as a fluctuation on the liquid surface. However, on fractal gel surfaces, different spreading dynamics [theta(D)(t) proportional to t(-0.58)] were observed, although Marangoni flow still occurred. We found the surface-dependent spreading can be discussed in terms of competition between Marangoni flow and the pinning effect due to surface roughness.