The flow in symmetrical and nonsymmetrical rectangular section scroll is studied by numerical simulation method based on 3-D N-S equation and structured multi-grid.Baldwin-Lomax model is adopted for turbulence enclosure.Results show that: flow features at the scroll outlet are fundamentally similar for axisymmetric and non-axisymmetric configuration.Peripheral uniformity in non- axisymmetric scroll is somewbat better than that in axisymmetric one.in non-axisymmetric scroll pressure gradients appear on the cross sections in the later 1/4 flow channel,which are responsible for the secondary flow losses.