Chemistry has characterized experimental science and applications, so building and developing a system of practical exercise perfectly and suitably for students' capacity is in fact vital to apply them regularly in teaching and learning chemistry. Based on the principles and building processes of CPE, the authors have selected and built a system of exercises with more than 500 appropriate CPE which can be applied to the lessons of advanced chemistry 11th grade and more than 100 CPE used for training gifted students at all levels. These are mainly taken from the references from the foreign or international examinations and documents. Having conducted the experiment in two advanced class 11th at Le Quy Don specialized high School - Binh Dinh, the results of pedagogical experiment demonstrate that the system of CPE was well-selected, which improved students' ability of acquiring chemical knowledge and their development of critical thinking.