The state of the art of high repetition rate mode-locking technology is introduced. Recent developments of high repetition rate mode-locked solid-state laser are described briefly, followed by a detail review of examples. Mode-locked solid-state lasers are known with high output power, high repetition rate and good stability. Scaling up the repetition rate of solid-state lasers may not only benefit optical metrology and provide a new time-frequency reference, but also find applications in space communications, laser radar and other research fields.