The synthesis by in situ oxidative polymerization of poly(5-methoxyl-2-(3-sulfopropoxyl)-1,4-phenylenevinylene) (MPS-PPV)/poly(3,4-ethylenedioxythiophene) (PEDOT) composite particles with high surface area in aqueous dispersion of MPS-PPV was reported. The nanostructure and growth mechanism of MPS-PPV/PEDOT composite particles were investigated in detail by FE-SEM and TEM, as well as XRD. PEDOT appeared to have used the tangled-worm like structures of MPS-PPV assembled in the presence of FeCl 3 as a scaffold for polymerization, wrapping itself around the tangled worms like bark on a tree. Cyclic voltammetry (CV) was used to qualitatively characterize the pseudo-capacitance properties of MPS-PPV/PEDOT composite particles. Their mass-specific capacitance and cycling stability were calculated by cyclic voltammetry cycles at different potential scan rates. The results showed that the maximum mass specific capacitance for MPS-PPV/PEDOT composite particles increases with the increase of the weight ratio of MPS-PPV, which can be achieved as high as 102Fg −1 . Moreover, the materials exhibited high cycling stability and retained approximately 45% of their maximum total capacitance, which was higher than that of pure PEDOT (approximately 40%), as the scan rate approaches 25mVs −1 . These results make the composite materials available in the field of electronic devices.