The present invention relates to a quinoline derivative represented by general formula (I) or a pharmaceutically acceptable salt, hydrate, solvate or prodrug thereof, wherein Ar, R1, R2, R3, X, Y and n have the meanings given in the description. The present invention also relates to the comparatively strong effect of the compound represented by general formula (I) on inhibiting c-Met kinase. The present invention further relates to the use of this compound or a pharmaceutically acceptable salt, hydrate, solvate or prodrug thereof in the manufacturing of a medicament for treating the disease caused by abnormally over-expressing c-Met kinase, in particular, for treating or preventing cancer.
