Based on the analysis of the structure of Lagrangions, a new general method and 6 special methods for the construction of Lagrangians for one dimensional system from the motion equation directly were presented. By use of the metthods, some Lagrangians of the differetial equations were derived. By means of the direct approach, it is verified that a system may have many different equivalent Lagrangians, even an infinite family of Lagrangians. The approach presented is a way to obtain Lagrange symmetries and the conserved quantities.