A novel scheme based on cross-gain modulation in cascaded single-port-coupled se miconductor optical amplifier(SOA) is studied theoretically and experimentally. Theoretical model for the single-port-coupled SOA is established for theoretical simulation and performance evaluation.The 10Gb/s all-optical logic AND operatio n has been demonstrated theoretically and experimentally. A parameter is exploit ed to evaluate the output performance. Results show that the output performance is tightly related to input power and input extinction ratio. Theoretical calcul ation results are in agreement with the experimental results.