An all-optical logic AND gate based on two-photon absorption (TPA) in semiconductor optical amplifier (SOA) is simulated. By solving the rate equations of SOA in the form of a Mach-Zehnder interferometer (MZI), the performance of AND gate is numerically investigated. The model takes the effects of amplified spontaneous emission (ASE) and pulse energy on the system’s quality factor (Q-factor) into account. Results show that the all-optical AND gate based on TPA in SOA-MZI based structure is feasible at 250 Gbit/s with a proper Q-factor.