Polyaniline(PANI) microwires and microspheres containing Au nanoparticles were prepared using different organic acid as dopant by an in-situ polymerization method. When L-CSA was used to synthesize PANI/Au composite, microwires were obtained. While by introducing hydrogen bonding and/or electrostatic interactions between mercaptocarboxylic acid capped Au nanoparticles and aniline molecules, microspheres were synthesized. SEM and TEM indicated that the diameter of the microwires was about 200 nm and the diameter of the microspheres was between 1 μm and 3 μm. FTIR and XRD characterized the structure of the PANI/Au composite microwires and microspheres.