The study was performed with the help of a questionnaire of views of senior schoolchildren about the objectivity and stressfulness of various forms of the control of knowledge, the level of stress in the exams and measures for its reduction. 53.4% out of the students assess their knowledge in this area as insufficient. The most objective form of the control students consider an oral exam, the least stressful--blank testing. After passing the exams in class 9 we observed the evident reduction of representations of the objectivity of test forms of control. The necessity of the activization of educational work with students on the issues of prevention of exam stress and methodological work on perfection of the organization and content of the forms of Knowledge control is showed.