Objective: This study aimed at comparing the descriptive assessment in terms of critical and creative thinking of sixth grade students in the public and private schools of district four in Karaj. This is a descriptive research which is done in a causal-comparative method. Methodology: The population consisted of all sixth grade students (girls and boys) in the public and private primary schools. According to the information, the total number of students was 8529 people, which 7788 of them were selected among public school students and 741 of them were selected among private school students. The sample size of 368 was determined by using Morgan table, in which 330 of the samples were belonged to the public schools and 38 of the samples were students of the private schools. Stratified random sampling method was used as the sampling method. This research was employed Critical Thinking Dispositions Questionnaire with the reliability of sub-scales of creativity= 0.75 and commitment=0.86; and Torrance Test of Creative Thinking with reliability between 0.80 to 0.90; and descriptive Transcript of Records. SPSS software is used to show the results in both descriptive and inferential statistics (T-test). Results: Results showed that there is a difference between descriptive assessment in terms of creative thinking among sixth grade students in the public and private school district four in Karaj; but, the difference was not observed the critical thinking. Among all the variables of creative thinking and its dimensions (invention, extension, fluidity, flexibility, and creativity), descriptive assessment of the majority of students in the public and private schools was greatly good; however, it was better in the public schools than the private. Conclusion: Among all variables of creativity, commitment and critical thinking, descriptive assessment of the majority of students in the public and private schools was acceptable.
