Phosphoric acid is a strong acid or a weak acid. This is a common problem in chemistry. The distinction between phosphoric acid and its sex quality is related to many chemical reactions. Yes, it is argued that phosphoric acid can be partially ionized in water, according to the method of acid, strength, determination, strong acid, in water, complete, ionization, and phosphoric acid, not so, therefore, can be broken, it is weak acid. However, there are also points of view, saying that under certain specific conditions, it is quite acidic and strong, and it cannot be discussed only by conventional methods. In short, the strength of phosphoric acid, on the basis of, need, synthesis, consideration, its environment, reaction system, etc., can only be obtained due to factors, a more accurate one. If only in the general situation, phosphoric acid is usually regarded as a weak acid.