The most effective factors to the dimensions of deposit layers in the laser rapid forming (LRF) processing have been achieved through using orthogonal regression design (ORD) and regression analysis method. The most effective factors on the height of deposition layer are powder feeding rate and scanning velocity. And the most effective factors on the width are spot diameter, scanning velocity, and interaction between laser power and spot diameter. The approximate relations between the deposition layer dimensions and their most effective factors are obtained and validated.