This paper introduces two examples of organic thin film growth on in plane heterogeneous substrates. One is growth of pentacene films on SiO₂ with metal electrodes, in which nucleation and initial growth process was observed real time by photoemission electron microscopy. Another is growth of sexithiophene (6T) films on SiO₂ with periodic grooves (graphoepitaxy). Elongated 6T grains could be obtained along the groove under an optimal growth condition. The mechanism of these growth processes could be basically understood according to a conventional thin film growth theory.