Guqin mainly adopts the three-point profit and loss method. "Three-point profit and loss method" is the earliest complete temperament theory in the history of Chinese temperament. It is called "the ancestor of temperament" and appeared around the middle of the Spring and Autumn Period.

"Guanzi·Diyuan Chapter" says: "Everyone will play five tones, several songs, the first master one and three, for the hundred and eight, for the emblem. It is not that there are three points and go away from their vehicles, which is suitable for commerce. There are three points and When it is restored to its place, it is born. There are three points to multiply it, and it is enough to form an angle." The three points of profit and loss contain two meanings, one of three points of loss and one of three points of profit.

According to a specific string, remove one third of the string, that is, the third loss is one, and the upper fifth of the string can be obtained; increase the string by one third, that is, the third gain, can be obtained. The lower fourth of the string. Starting from uniformity, the above two methods are used alternately and continuously, and each temperament can be generated. The record of the "three-point profit and loss method" was first seen in "Guanzi·Diyuan", and only five tones were counted. By the time of "Lüshi Chunqiu·Yinlu", the length specification of the twelve laws had been calculated by this method. According to the order of the "three-point profit and loss method", the rhythm of the upper fifth is called "Xiasheng" in ancient times; the fourth is the only rhythm in the lower part, which is called "shangsheng" in ancient times. From the source of uniformity, five times below and six times above, the twelve laws can be derived.

In addition, the overtones of the guqin just coincide with the pure temperament, and the pure temperament is a temperament generated on the basis of the overtone sequence. Although there is no theory about pure temperament in ancient China, the third, sixth, eighth, eleventh and other four emblems of the lyre are, in turn, one-fifth, two-fifth, three-fifth, and so on. Four out of five, the denominator of the ratio is five, which is unique to pure law. Therefore, Mr. Yang Yinliu pointed out: "If a qin piece uses the overtones on the three, six, eight, and eleven emblems, the temperament used in this piece can only be pure temperament." From the piano score "Jie Shi" Looking at the overtones on the sixth, eighth and eleventh emblems in Tiao·Youlan, it can be confirmed that pure temperament has been applied in China in the sixth century AD.

It can be seen from the above that Guqin mainly uses the "three-point gain and loss method", and the music with more overtones can be regarded as a mixture of "three-point gain and loss method" and "pure temperament".