Abstract: Culmann’s graphical construction is ameliorated. By artfully constructing lines and considering geometrical aspect combined with physical aspect, a new form of formula for active earth pressure is derived,and then a new graphical construction is developed. Compared with Culmann’s graphical construction, the ameliorated approach needs fewer calculations and is more convenient, but the result obtained is preciser. The example shows that the result of it is in good agreement with that of Coulomb’s earth pressure theoretical formula.