Interfacial microstructure tunable photovoltaic effects have been reported in heterojunctions of ${\mathrm{La}}_{1-x}{\mathrm{Ca}}_x{\mathrm{MnO}}_3$ thin films and tilted or exact cut Nb-doped ${\mathrm{SrTiO}}_3$ single crystal substrates under irradiation of UV pulsed laser. The photoresponse times of vicinal junctions and films were obviously faster than those of exact cut samples. The behaviors can be explained by the slope of the built-in electric field in the $10°$ tilted heterojunction and the interfacial terrace microstructure of ${\mathrm{La}}_{1-x}{\mathrm{Ca}}_x{\mathrm{MnO}}_3$ films.