and critical thinking before and after learning through the Big Six approach. the research samples consisted of 21 prathomsuksa 5 school under the Office of the private education commission, Maha sarakham province. They were selected by cluster random sampling. The research instruments were 8 lesson plans, a information literacy test and a critical thinking test. The trial was conducted for 8 weeks, 2 hours per week, for a total of 16 hours. The statistics used for data analysis were percentage, mean, standard deviation and dependent sample t-test. The results of this research were as follows: The students' Information literacy skills before the instruction were 10.00 or 41.07 percent, after the instruction by the Big Six approach were 21.76 or 90.67 percent by which was higher than the set criterion of 80 percent and the mean after studying was higher than before studying The students' critical thinking before the instruction were 8.23 or 39.52 percent, after the instruction by the Big Six approach were 17.42 or 87.14 percent by which was higher than the set criterion of 80 percent and the mean after studying was higher than before studying.