- The purpose of this study is to develop a scale to determine secondary school students' conceptions of learning biology and conduct the reliability and validity study of the scale. A total of 997 students from two independent samples attending 9th- 12th grades participated in this research. The research data is obtained from the 5-point Likert type scale with 41 items. The results of the explanatory factor analysis (EFA) indicated that the factorial structure of the scale includes 5 subscales with 29 items. It has been found that overall Cronbach Alpha for the scale is .78 and .76, .71, .65, .73, .82 for the subscales respectively. The results of the confirmatory factor analysis (CFA) indicated that the factor structure fit the data. It is concluded that Conceptions of Learning Biology Scale (CLBS) produces reliable and a valid results for measuring the conceptions of learning biology of secondary school students