 Thammarak is of Chinese descent.Thammarak born on July 22, 1938 in Roi Et Province, is married to Wanida Isarangkun Na Ayuthaya.He graduated from Prachawittaya School and Buri Ram boarding school, Secondary school from Suankularb Wittayalai School, and Amnuay Silpa School and then Bachelor of Science from Chulachomklao Royal Military Academy Class 10 and National Defense College, Class 34.