Abstract: Chemical constitution of Pinus kesiya oleoresin from Burma was analyzed by GC-MS.Twenty four compounds were separated and identified, which account for 94.4% of the total content. There are 5 kinds of monoterpinene with content of 41.39%, 5 kinds of sesquiterpinene with content of 11.28%, and 14 kinds of diterpinene with content of 41.73%. Compared with oleoresin of P.kesiya var.langbianensis (A.Chev.) Gaussen from Yunnan of China, the main components and contents of monoterpinenes and diterpinenes were similar, but the chemical components and contents of sesquiterpinenes were different, and β-ylangene is a characteristic component in P.kesiya oleoresin from Burma.