Therefore an evaluation stability on the system power distribution make the exiting system can survive and back when distruption or after distruption. The test system IEEE 30 buses modification represents data distribution system of electric power as database, a method of Newton-Raphson, a method of RCF (Reactive Contribution Factor), and the principle of a method of LSF ( Loss Sensitivity Factor) is a effective methode for an optimalization in distribution system. On this optimization, an additional Capasitor can incress a voltage profil and reduce a total losses as much as 1,21 % with 10 Mvar injection on bus 26 and 30. Then an additional Distributed Generator the system reduce a losses as much as 3,3 % with a LSF methode and 9,03 % used scenario 1.