Chandravyakaran (c 470)  a system of Sanskrit grammar propounded by Chandracharya or Chandra (Gomi), a pioneer grammarian of the Bengal school. The earliest reference to him is by Bhartrhari (c 650 AD) in Vakyapadiya. The work is based on Trimuni Vyakaran, a system of grammar formulated by Panini, Katyayana and Patanjali. Chandracharya's purpose was to improve upon the Paninian system. He omits Panini's Vedic rules but includes certain Vedic roots (dhatu) in his list of roots (Dhatupath).

The fourteen maheshvarasutras of sanskrit alphabets are reduced to thirteen. Certain pratyaharas (comprehension of several letters by one syllable) of Panini are omitted in the Chandravyakaran, and some new ones formulated. In many cases Panini's sutras (rules) are recast, apparently for ease of pronunciation. Eighteen rules are Chandracharya's own addition, and these have been incorporated in the Kashika by Jayaditya and Vamana (middle of 7th century). The Chandravyakarana, as available now, is divided into six chapters (adhyayas) of four sections (padas), each comprising 3,099 rules in place of Panini's 3,981. The grammar contains no technical terms and, accordingly, is called asangjnakang vyakaranam.

There is a commentary on the Chandravyakaran, said to have been composed by Chandracharya himself. The accessories of the Chandravyakarana are a list of rules for the suffixes (unadisutras) in three parts (padas), a list of roots (dhatupath) in ten sections, rules for gender (linganushasana), a treatise on prefixes (upasargavrtti, available in a Tibetan version), rules on sounds (varnasutras), and rules on grammatical dicta (paribhasasutras). [Pratap Bandyopadhyay]