Teaching according to the two-year curriculum has continued until 1939. After that, only 25 students from Grade 8 graduates who have passed competitive examinations per year have been accepted and renamed the Forest School. The “Forestry School” during this period has changed the course from 2 years to 3 years and graduates will receive a Diploma in Forestry. But only those who graduated from Maejo Kasetsart College Preparatory School will be accepted. And has continued to do so until the year 2490, thus accepting students from graduates of pre-university education in general. During this period, the name of Forest Science School was changed to "College of Forestry"

The bachelor's degree program has been improved from 5 years to a 4 year program with 3 majors, namely general forestry. Department of Conservation and product cycle Open for graduate studies The Master of Science (Forestry) program and the improvement of the bachelor's degree program are divided into 2 disciplines, namely Forest Resource Management. and product cycle Subsequently, the bachelor's degree program was improved divided into 3 disciplines, namely Forest Resource Management. Product Cycle and forest biology