also known as Gu-qin or chin is a seven-string plucked zither of China. Gu-qin means ancient qin and belongs to the zither family of East Asia. The soundboard is made of wutong wood (Firmiana platanifolia) with no fret and bridge, and the bottom board is made of zi wood (Catalpa kaempferi). The surface of the gu-qin has thirteen inlaid markers, which usually made of mother-of-pearl, gold leaf, or precious stone.

The qin has a history of 3000 years, part of which predates accurate documentation. A legend states the qin was invented by Fuxishi, a mythical half-dog half-human character. The qin became the representative of music in Chou dynasty (1155 B.C.). Its seven-string form and its ideology were standardized in Han dynasty (202 B.C.). Traditionally the strings of the qin were made of silk. However, since it was very hard to get good quality silk to make qin strings, they were replaced by steel strings wound with nylon. Today people are trying to reproduce silk-strings, so hopefully the quality of the traditional tone of qin can be heard again.

There are four categories of traditional Chinese music: folk music, court music, religion music, and scholar music. The qin belongs to the last category. Many scholars of that time were qin players such as Confucius. Throughout Chinese history, every scholar has to learn four art forms: qin (qin music), qi (chess), shu(calligraphy) and hua (painting). The fact that the qin was considered the primacy act tells us of its significance.

The qin accumulated an abundance of lore and anecdotes. It has the thought of Confucianism and Taoism. For example, the qin has three kinds of tone color: harmonic, open string and glissando. They represent respectively heaven, earth and mankind.

Also the instrument itself involves the cosmology and metaphysics. The length of the qin was 3 feet and 6.5 old Chinese 'inches' which symbolized the 365 days of the year, and the longchi (dragon pond, the larger of two sound openings in the bottom board) was 8 'inches' which symbolized the eight directions in which the winds blew.

Another unique characteristic of the qu-qin is that it has its own musical notation that is completely different from other instruments, which called jianzipu (simplified character notation, see example below). This kind of notation has no rhythmic indication. Therefore, one will never hear the same music with the same rhythm from two players, even though they may study with the same master. Thus, it gives ample space for the player's interpretation and expression.