A novel on chip automatic tuning circuit for Gm ¡V C continuous time filter is presented. The circuit is composed of an integrator, a frequency tuning circuit, and a Q tuning circuit. A 4th order Chebyshev low pass filter is also designed with the tuning circuitry. All circuits are designed by using the parameters of TSMC 0.25um process. The power supplies are ¡Ó2.5V, and the cutoff frequency is 10MHz. The main LPF exhibits passband ripple below 4dB, and stopband attenuation over 70dB. The equilibrium time for tuning circuits is less than 3£gseconds.