Using a new pulsar timing system at the 25-m radio telescope of Urumqi Astronomical Observatory, we have detected a large glitch in the Crab pulsar which occurred in 2000 July. The size of the gfitch is Av/v ～ 2.4 × 10-8, with a rela tive increment in frequency derivative Av/v ～ 5 × 10-3. The observing system is introduced and the observed properties of the glitch are discussed.