Provided is a method of preparing a thin film structure having anisotropic, transparent, electroconductive, flexible properties. The method of preparing a thin film structure includes providing a growth substrate; growing silver nanolines on the growth substrate by using a lightning-rod effect; molding the silver nanolines by using a polymer; and separating the silver nanolines molded by the polymer from the growth substrate to form a freestanding anisotropic, transparent, electroconductive, and flexible thin film.