We propose a technique of multi-channel speech enhancement based on integration of beamforming and statistical model-based speech enhancement to clearly extract the target speech, even in very noisy environments. Conventional microphone array-based techniques estimate speech and noise power spectral densities (PSDs) from the spatial cues of the sound sources; however, their estimation errors dramatically increase when there are many noise sources. We integrated clean speech models trained in advance and the noise PSDs estimated in beamspace to compose observation models and designed a precise Wiener lter. Experiments under adverse noise conditions showed that the proposed technique signi cantly improved the signal-to-noise ratios (SNRs) compared with the conventional microphone array processing technique.Index Terms-Microphone array, beamforming, power spectral density estimation, statistical model, Wiener lter.