To use: o-Toluidine is an important intermediate in the production of dyes and pigments, can be used for the preparation of direct red 62, red RL, red G, jujube red GBC, basic fuchsin, chromosol AS-D, acid red 35/155/265, solvent red 124, azo dye diazo components and coupling components, to produce organic pigments yellow 14/17, blue 19; Pesticide raw materials, the production of pesticide fungicide "tricyclazole", insecticide borers, acetamidine; Herbicide acetochlor; Raw material of rubber vulcanization accelerator; Saccharin raw material; Corrosion inhibitor raw materials, etc. In organic synthesis, O-toluidine is also used to synthesize heterocyclic compounds such as indole and its derivatives.