All-optical buffer can store the packet, which can solve the problem of node collision when transmitting packets in optical domain, and will become an important element in all-optical network. This paper presents a novel erasable all-optical buffer which realizes the “write” and “read” function. Two semiconductor optical amplifiers (SOA) which are used as the nonlinearity element can also compensate the power attenuation at the same time. Compared with the single semiconductor optical amplifier configuration, the storage time is prolonged greatly when the same signal power is introduced. This configuration can overcome the “packet leakage” effectively on the output port because of the “write” operation. The buffer can store the packet transmitting at the speed of 2.5 Gb/s successfully.