Abstract: With the linear regression method, all the straight edge forming parameters of Φ610 mm ERW mill located in Baosteel is calculated, covering those for the three critical and the most flexible parts, i.e., edge bending, preforming and linear forming. Meanwhile, with the quadratic regression and as per the downhill process, the bottom roll data are also optimized, actually resulting in the so-called Flexible Forming. As a result, the forming parameters as determined by statistical analysis have been used for massive pipe production with the said Baosteel Φ610 mm ERW mill.