This paper proposes a new log-domain realization of biquadratic filter, which is systematically derived using the two-integrator-loop and state-space synthesis procedure. The filter is constructed with two integrators and current summer circuit. This biquadratic realizes highpass filter, bandpass filter and lowpass filter simultaneously. The proposed filter has a simple structure and can be electronically tuned. PSPICE simulations are given to confirm the theoretical analysis.