The Truss Structure consists of members/elements that takes only tension or compression and no bending moment in what so ever form. In the engineering term the Truss is defined as the two-force member, where the members are so assembled that the assemblage works as a single unit. The truss structure is generally provided when we need a large open space. In this study we are presenting Non linear analysis of three different type of truss arrangement i.e. Flink, Howe and King post for long span open area of dimension 35m x 25m. In this study we will also discuss the variations occur due to different type of sections such as ISMB, Channel section and Angle section. For analysis purpose we will use staad.pro