Recent years, the Chinese government have been pouring funds into institutions of higher education, in the hope that China, over four decades’ reform and opening, could someday take the lead in science and technology as well. For this reason, institutions of higher education are exploring methodologies to usher in innovation. Problem Based Learning (PBL), among others, is a tentative attempt to implementing changes in the educational models of higher education, particularly critical thinking. However, this process does not occur spontaneously, the variables in the process might decisively influence the level of achievement. This paper analyses the most important variables of the PBL and the teaching of critical thinking skills, hoping to map out possible pieces in the puzzle.