The earliest recorded history of the Chinese guzheng appeared in the Qin dynasty, about 237 BC. Since then, the guzheng has gained in popularity among the Chinese people. The ancient guzheng was a 5-string instrument. Later versions contained 12 and then 13 strings. The modern guzheng has 21 strings, However guzhengs with 23 or 25 strings are also available. The earliest guzheng strings were made of silk. Now the strings are made of steel wound with nylon. Through successive innovations and advancement of performance skills, the guzheng stands out among other traditional Chinese musical instruments.
From its beginning, the guzheng gained popularity and spread from province to province. As it spread, it became integrated with regional operas, stories, and music. Each of the regions developed their own musical themes and performing techniques which gradually coalesced into five major schools: Henan, Shandong, Chaozhou, Zhejiang, Kejia. The Henan school is characterized by its spiritedness and liveliness - it draws from a large repertoire of folk drama and minstrelsy. The Shandong school is more balanced - both rugged and passionate. The Chaozhou School is tender and sweet. The Zhejiang School is delicate, quite suited to the musical flavor of southern Chinese string instruments. Lastly, the Kejia school is marked by its unsophisticated and primitive style.
Traditionally, The guzheng was played by means of the right hand plucking strings on one side of the bridge and the left hand stopping or vibrating the string on the other side. Nowadays, the left hand may also be used to pluck strings in concert with the right hand in addition to its more traditional role.
The guzheng's popularity has led to the establishment of a zheng department in most musical conservatories in China.