This work reports a facile method to create efficient natural textile based triboelectric nanogenerators (N-TENGs). First, plain natural textiles, cotton and silk, were dip-coated in cyanoalkyl silane and fluoroalkyl silane to transform their surface energy into positive and negative triboelectricity. The N-TENGs were fabricated by stacking an cyanoalkylated siloxane grafted fabric with an fluoralkylated siloxane grafted fabric to assemble a Cu fabric electrode. A single N-TENG generated a maximum output voltage and output current of 216.8 V and 50.3 μA (0.87 μA cm-2), without any nanopatterning. The double stacked N-TENG showed an enhanced output current of 84.8 μA (1.46 μA cm-2), and exhibited a maximum power output of 0.345 mW cm-2 at an external resistance of 0.42 MΩ. In addition, the N-TENG can light up 100 light-emitting diodes (LEDs) and charge capacitors, demonstrating its self-powering applications.