Para-aminosalicylic acid is a chemical substance that is a white or slightly yellowish powder that irritates the respiratory tract and skin mucous membranes, and is more irritating to the eyes. It is mainly used in the treatment of tuberculosis infections and can act as an antibacterial agent, inhibiting the growth and reproduction of tuberculosis bacteria through competition for the synthesis of folic acid. In the case of tuberculosis infection, this drug can be used in combination with other anti-tuberculosis drugs for treatment. After oral administration, it may cause itching of the skin and soreness of the joints, and it also tends to cause fever, which is more irritating to the gastrointestinal tract, and needs to be taken orally correctly under the guidance of a doctor. For the liver and kidney function is not good, there is a great impact, easy to aggravate the liver and kidney function, it is better to choose other drugs.