Logical thinking includes scientific knowledge and skills to understand hypotheses that depend on theory, statistic, cause and effect. Logical thinking and using reasoning skills play an important role for students' academic achievement, understanding scientific concepts and nature of science. The students who can use these skills can construct hypothesis, and test this correct or incorrect into their mind. Moreover, they can solve higher order problem and transfer reasoning skills to different or new problems. This situation is important for science education since students should these skills effectively in physics, chemistry and biology courses. In the present study, science and primary education prospective teachers' reasoning levels were determined and investigated whether there was effect of some variables such as mother-father education state, classroom level, gender on prospective teachers' reasoning levels. Hence Lawson's Science Reasoning Test was applied to 795 science and primary education teacher candidates in Turkey. It was found that the science and primary education teacher candidates' reasoning levels were slightly below medium-level and there was no significant meaning between science and primary education teacher candidates' reasoning levels. The effect of some variables on teacher candidates' reasoning level was detailed in the section of finding.