With the mixed melt salt of AgNO3 and KNO3 used as the ion source, the influences of technological parameters, including melting salt ratio ,exchange time and temperature,on the characteristics of the ion-exchanged K 9 glass waveguide,were investigated systematically. The index profile of the waveguide was found to accord with the Gauss function,and the relationship between the waveguide performance and process parameters was established. The transmission loss of the ion-exchanged planar waveguide was measured to be 0.45 dB/cm. A racetrack resonator filter was fabricated by ion-exchange in K 9 glass and its filter effect was realized.