This paper presents a new rnethod for analysis and computation of steady-statereal power security region by linear programming.In this method based on the D.C load flow,theupper and lower bounds of the hyper-cuboid explicit steady-state security region are chosen asunknown variables.The objective function is the total amount of the adjustable generations withweighting factors.The model of the steady-state real power security region is changed in to the proposed linearprogramming methed for ealculation.The numerieal exarnples are tested on IEEE 6-bus and 30-bussample systems.The computational resuIts showed the proposed model a nd algorithm feasible andeffective.