The aimed of this thesis to fevelop a computer programme to carry out the performance analysis of steam power plant cycle. irs scope is limited to the analysis of the Rankine steam power cycle whicah is widely used. it utilizes the basic equations in power plant cycle analysis and the equations in calculating the internal properties of steam at various states. The primary purpose of this programme is to the determine the performance steam power plant together with ploting the T-s-Diagram of the processes involved for the existing steam power plant in the Thermodynamics Laboratory of Mechanical Engineering Faculty, Universiti Teknologi Malaysia.