This paper describes a generalized dynamic model of multi-machine power systems for transient stabilityanalysis and its computer simulation using MATLAB/SIMULINK. The generalized model of the power systems can beused for teaching the power system transient phenomena, as well as for research works particularly to improvegenerator controllers with advanced technologies. Constructional details of various sub-models for the whole powersystems are given and their implementation in SIMULINK environment is outlined. The developed simulation model istested on 3-machine 9-bus power system and 10-machine 39-bus New England power system under different largedisturbances. For the studied cases, the critical clearing times (CCT) are calculated and the simulation results arepresented and discussed. Nonlinear time-domain simulation results obtained from several case studies validate theeffectiveness of proposed model for transient stability analysis. The proposed dynamic model has been employed tosupport and develop power engineering education at both the undergraduate and graduate levels. Likewise, foracademic and educational use, all component sub-models are transparent and can simply be modified or extended.