The purposes of this research were to examine the learning outcomes and problem solving transfers of undergrad students who learnt with web-baed learning environment for knowledge construction(WLKC).The participants in this study comprised 41 undergraduate student teachers in computer education program.The research design of this study was pre-experimental research.Both quantitative and qualitative data were collected and analyzed.Means and standard deviations were employed to analyze the learning outcomes derived from the transfer and retention test.Moreover,protocal analysis from the interview was employed to analyze the student teachers problem-solving transfer.The result revealed that 76%of them showed improvement of learning outcome following constructivist way,whereas 24%of them showed the outcome of rote learning.In qualitative part,the result indicated that the problem-solving transfer was achieved by the constructivist student teacher through retrieving mental model with previous situations to solve new and different problem contexts and then the transfers occurred between similar contextual problems.