The disclosure discloses a thin film transistor and a manufacturing method thereof, a liquid crystal display panel, a transition pattern is disposed between a doping pattern and a source electrode pattern, the transition pattern covers sidewalls of the source electrode pattern and the drain electrode pattern respectively to insulate an active pattern and the sidewalls of the source electrode pattern and the drain electrode pattern in direct contact, so as to reduce leakage current of a TFT. Moreover, two sides of the transition pattern adjacent to the active pattern are covered by the doping pattern, which can reduce contact impendence of the active pattern and the source electrode pattern as well as the drain electrode pattern, so as to prevent the problem of insufficient charge of the TFT.