The opportunity of inkjet printing for the fabrication of metal electrodes in electronics applications has been explored for years but the direct fabrication of fine metal electrodes in the scale of tens of micrometers and less has suffered from its limited resolution and reliability. Moreover, the imperfect wetting control of silver ink has caused the short circuit formation between adjacent electrodes, even with a surface energy patterning technique. In this study, a novel self-patterning technique is introduced, which has the capability to convert metallo-organic silver ink to either conductive or non-conductive patterns, as intended. It is found that polyaniline allows the infiltration of metallo-organic silver ink into the voids among polyaniline granules and inhibits the formation of networked silver nanoclusters after a thermal process. With the fusing control layer of polyaniline, conductive and non-conductive patterns were successfully self-differentiated, no matter where metallo-organic silver ink lied down, and the line resistance of the self-patterned metal electrode as fine as 96 μm in line width and 27 μm in line space was as low as 27.55±0.62 Ω/cm.