This paper investigated online collaborative learning on students' learning outcomes in higher education with an online platform called GMoodle that was implemented at The Education University of Hong Kong. To discover the benefits and drawbacks of online collaborative learning, students were invited to join this exploratory study and complete the pre and post questionnaires to evaluate their learning outcomes. The quantitative and qualitative studies of 75 undergraduate students were conducted based on the questionnaires and focus group interviews, and the results showed that students' learning outcomes especially self-management skills and collaborative skills were enhanced through the online collaborative activities. Before launching GMoodle, trainings were provided for the in-service and pre-service teachers. Most of them reflected that GMoodle is a useful platform for educators to understand students' learning progress, promote active collaboration and facilitate team teaching across different disciplines. Not only the students but also the teachers benefited from this online learning platform for collaborative learning, fair assessment, and team teaching.