A low-threshold self-starting Kerr-lens mode-locked Ti:sapphire laser was demons trated by use of a tight focusing cavity design and a semiconductor saturable-ab sorber mirror (SESAM). With a 3% and a 12% output couplers, we achieved mode-loc king thresholds as low as 390 and 600mW, respectively. Stable femtosecond laser pulses with average power of 114mW were generated for pump power at 12W, which corresponds to a typical duration of 17fs and bandwidth of 47nm. The pump power range for mode-locking covers from 600 mW to 48W at a 12% output coupler, an d the mode-locking stability is improved.