Introduction: Motivation is important as one of the major factors for incidence of behaviour in all behaviours such as learning, performance, perception, accuracy, recall, forgetting, thinking, creativity and emotions. The interaction of trainers and nursing students plays a significant role in clinical education and achieving educational objectives. Aim: Considering the wide role of nursing trainers in students leaning clinical experience and their motivation, and based on qualitative studies done so far, the present research was performed to investigate the relationship between educational behaviours of clinical trainers and motivation toward science learning among nursing students. Methods: This cross sectional study was performed on 200 nursing students, third-eighth semester, at a nursing faculty from 1 January to 30 July 2019 at Zanjan university of medical sciences, Iran. The students were included though census. Confidence interval of 95% and a significance level of Pvalue less than 0.05 was considered significant. Results and Conclusion The mean age of the students was 22 years. This study showed that the level of educational behaviours of clinical trainers had a direct correlation with the score of learning motivation subscale of students. It also had a direct significant correlation with the total score motivation toward science learning (p=0.01). The behaviours of clinical trainers and understanding of nursing students about the characteristics of trainers are important in creating motivation, facilitating learning, and improving nursing education.