A new type of Q -switched pulsed lasers (CPQL, Controllable Passively Q-switched Laser) is presented. The laser is composite of a passively Q-switched laser with a saturable absorber and a controlling LD with a focus system. The performance of the laser output pulses, including the pulse energy, pulse width, pulse generation moment and repetition frequency, can be actively controlled by the operator with the controlling LD. The new type laser is discussed theoretically and the experiment results are present. Compare to the ordinary Q -switched laser, including passively Q-switched lasers and actively Q-switched lasers, CPQL"s have higher performance and will find important applications in many fields.© (2005) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.