Widespread energy harvesting, generating self-sufficient power from the surrounding environment, such as wind, solar and geothermal, have attracted increasing attention in the past decade due to the energy crisis and global warming. Most recently, a new type of power generating device, named as triboelectric nanogenerator (TENG) based on triboelectric effects coupled with electrostatic effects have been demonstrated as powerful means of harvesting mechanical energy from living environment. Here, the polyimide (PI) polymer was synthesized by changing different dianhydride and diamine monomer to control dielectric properties and work functions. We report a new PI based TENG for effective dielectrics, resulting in 4.5 times higher output voltage and current of 30.2 V and 8.4 μA/cm<span style="font-size:10.8333px">2</span> at PI from Bis(3-aminophenyl) Sulfon (APS) based TENG compared to general Kapton based TENG due to the increase of dielectric constant of negatively charged layer and surface potentials on the triboelectric surfaces. Therefore, aromatic polyimides show a great promise in controlling dielectric properties of negatively charged layer in TENG and tuning the performance of polymer-based triboelectric devices for effective mechanical energy harvesting.