The general purpose of this research is to develop a scale in order to determine the bullying tendency of secondary school students and to realize validity and reliability study through this purpose. In this research, Bullying Behavior Tendency Scale (BBTS) is used. One hundred and fifty two students attending at 6th, 7th and 8th grades form the study group in scope of validity and reliability analysis. The scale’s internal consistency coefficient, item total correlation coefficient, test repeat test reliability, material reliability, scope, known group comparison and structure and criterion validities have been calculated. In reliability study, test repeat test results are found as .903. The highest reliability of internal consistency coefficient which was calculated for the general total reliability of Bullying Behavior Tendency Scale is found out to be Cronbach Alpha (.9545). Since Kaiser Meyer-Olkin value (.835) is bigger than .50, it is understood that example size is appropriate to make factor analyses. The measured feature is accepted to be coming from a multidimensional variable in universe parameter because Barlett test result is found meaningful, too. In the result of factor analyses made with Varimax rotated method, it is found that eigenvalue of first sub-dimension is 7.707, eigenvalue of second sub-dimension is 7.197, eigenvalue of third sub-dimension is 5.912 and eigenvalue of last sub-dimension is 5.404. These sub-dimensions are named as Physical, Verbal, Entertainment Target and Emotional Bullying.Key words: Bullying, behavior tendency, reliability, validity