An only one ns Nd∶YAG laser pumped narrow bandwidth pulse Ti∶sapphire tunable laser (by 532 nm) and a BBO OPA laser (by 355 nm) is reported. In experiment, a narrow linewidth (<0.1 nm) continuous tunable range of 570～670 nm Ti∶sapphire laser injection seeded BBO OPA with the laser energy output of 6 times in comparison with that of no seeded are achieved.