The synthesis and characterization of oligoaniline-containing dendron-rod-dendron dumbbell shape block oligomer (14G3A7) are presented. The unusual surface morphological evolution from fibrils to flat single-layer film and to a porous network is observed for 14G3A7 simply by oxidizing the block oligomer in solution. Based on the analysis of cryo-TEM as well as comparative studies on solution concentration and substrate properties, the series of changes in the surface morphology are explained through aniline conformational transition during oxidation. The network self-assembled from oxidized 14G3A7 contains a two dimensional close packing skeleton of aniline segment, which may find a wide range of applications in electronic sensitive devices.