Nowadays, We need graduate student who can utilize critical thinking and implement problem-solving skills at Clinical environment. Educational experts of new teaching methods believe that concept map could be an effective method among nursing students. Therefore, this study aimed to assess the effect of teaching clinical caring plan through the concept mapping on nursing students’ critical Thinking. It was a Randomized Controlled Trial research with control group; thus research sample included 34 senior nursing students at Abadan Medical Sciences College who were randomly divided into two equal groups whom were taught with clinical concept map drawing. Before vocational training, California-B critical Thinking questionnaire was handed out between two groups. Then a one-day workshop was hold to teach them, students were selected for concept mapping, how to be trained through the use of concept map using in caring plan. Both groups wrote and performed the caring plan in the neurology ward for the patients with CVA in 10 days in summer 2013. After vocational training, both groups were evaluated to assess the rate of their critical thinking. Findings showed that both groups’ performances were not significantly different in terms of gender, age, average scores and critical thinking at the beginning of the treatment. However, after intervening, the rate of students critical thinking in experimental group was significantly increase (Mean Rank = 24.88, p<0.001). The outcomes also indicated that the use of concept map as an Effective Intervention in clinical environment, therefore, could increase the nursing students’ critical thinking.