The purposes of this research were to 1) compare grade 12 students’ critical thinking ability after learning through problem-based learning with questioning technique and traditional method, and 2) compare grade 12 students’ learning achievement after learning through problem-based supplemented with questioning technique and traditional method. The sample were 637 grade 12 students were 16 class from Pathumthep Wittayakarn school in the second semester of academic year 2022. The sample was determined by using cluster random sampling, and using the classroom as the sample unit. They were divided into the 30 experimental group and 35 control group. The research conducted was Non-equivalent control group pretest posttest design. The research instruments consisted of 1) problem-based learning supplemented with questioning technique lesson 8plans the quality assessment of the learning management plan were at a 4.85 2) traditional method lesson 8 plans the quality assessment of the learning management plan were at a 4.85 3) critical thinking ability test has 20 questions the confidence value of 0.86, and 4) learning achievement test has 40 questions the confidence value of 0.79. The statistics for data analysis were mean, standard deviation, and t-test for independent samples. The research results were as follows 1. The students who received the problem-based learning with questioning technique had significantly higher critical thinking ability after learning than the students who received the traditional method at .01 level. 2. The students who received the problem-based learning with questioning technique had significantly higher learning achievement after learning than the students who received the traditional method at .01 level.