In this work, PANI/g-C 3 N 4 nanocomposites with different percent of g-C 3 N 4 were synthesized by electrochemical method and characterized by different spectroscopic methods including FT-IR, UV-Vis and X-ray diffraction (XRD). Also the morphological properties of synthesized nanocomposites were investigated by field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). In continues, the electrochemical and electrocatalytical properties of mentioned nanocomposites were explored. At the first part, PANI/g-C 3 N 4 coated on titanium and plated by silver, then the prepared electrode employed for electro-oxidation of hydrazine that shows good sensitivity. At the second part of research, PANI/g-C 3 N 4 was coated on FTO glass and used for electro-catalytic conversion of I - 3 to I - . The obtained data reveal that electrochemical activity of prepared nanocomposites are more than that for polyaniline. These results attributed to increase in rate of electron transfer due to presence of carbon nitride. Consequently, in the third part of work the nanocomposites were explored for supercapacitor applications. The nanocomposites exhibits good capacity that related to high porosity and surface area also fast electron transfer and performing red-ox reaction help this.