This research attempts to examine the collaborative problem solving methods towards critical thinking based on economy (AE) and non economy (TE) in the SPM level among students in the lower sixth form. The quasi experiment method that uses the modal of 3X2 factorial is applied. 294 lower sixth form students from ten schools are distributed randomly into 3 groups (KPMs1, KPMs2 and KKv). Two hypotheses have been tested. The ANOVA procedure was applied to detect whether there are significant differences in the mean score of critical thinking among these three groups. The research findings showed that students from the KPMs1 group obtained the highest mean score in critical thinking. Likewise, students based on economy in the KPMs1 group showed the highest mean score in the Cornell Post-Test (Critical Thinking). The implications of the finding are discussed.