The twin beams with high quantum correlation at 1 08 μm wavelength have been generated from the semimonolithic KTP OPO pumped by a frequency doubled and frequency stabilized Nd:YAP laser The parametric frequency down conversion with the type ⅠⅠ 90° noncritical phase matching has been achieved in the α cut KTP for the 0 54 μm pump power. The quantum noise reduction of 80% (7 dB) around 1 5 MHz on the intensity difference between the twin beams has been observed The pump threshold for the OPO is about 80 mW.