Abstract: The effective length factor method is still the most commonly used method for the stability calculation of a steel structure. The method avoids the complicated stability analysis on an overall structure and the core of the method is to determine the effective length of compression columns. In this regard, some formulas and tables are given in norms of Code for Design of steel structures, but the application of the formulas and tables is limited because of some assumptions, and it cannot be used to determine the effective length of columns in special cases (it is not universal). Therefore, the formulas and chart methods for determining the effective lengths of columns with different constraints are derived and made respectively in the paper. The chart methods can not only be used in regular cases in the above mentioned norms, but also in special cases. In addition, the use of chart methods is very easy and quick.