The present invention discloses a method and an apparatus for encoding and decoding video. A video decoding method comprises reconstructing a residual value by entropy-decoding received bitstream and dequantizing and inverse-transforming residual value information, generating a final prediction unit by performing inter prediction on a prediction unit which is partitioned from a coding unit into at least two prediction units by asymmetric motion partitioning (AMP), the two partitioned prediction units comprising a first partitioned prediction unit and a second partitioned prediction unit, and reconstructing a picture by adding the final prediction unit to the residual values.