This paper proposed a man-hour estimation method which was based on decision tree and model tree to solve the problem of inaccurate time quota in process industry.For the train set of mixed attribute types,firstly,the method used the nominal attributes to build the part of tree,and then used model tree method to construct each sub-tree.In addition,the proposed method could dynamic adjust training parameters when data-set changed.Finally,this paper used the actual production data of an oil refining enterpris...