This paper is written to report our research group's recent activities that are concerning quadruped locomotion control. To this end, we primarily constructed an electrically-actuated quadruped robot which is employed as an experimentation platform to test the locomotion control algorithm. An overall motion control scheme is introduced to reveal the main principles for achieving fast and agile locomotion scenarios. Having disclosed prototype development and real-time control procedures, trot-running locomotion experimental results are presented. In these experiments, the robot exhibited successful trot-running cycles in a repetitive, dynamically-equilibrated, agile, and compliant manner; demonstrating that the control algorithm has potentials to be utilized in fast locomotion tasks.