This research study on type of the joints and the deflection of bamboo truss in chiang rai the study of bamboo that is used in a tested 5 type Five kind of bamboo in this project were Phia-Bong (Bambusa nutans Wall),Phai-Sang (Dendrocalamus membranaceus Munro),Phai-Hia (Cephalostachyum virgatum Kurz), Phai-Ruak Dam (Thyrsostachys oliveri),and Phai-Wan (Bambusa burmanica Gamble). By test study the truss with the 3 pattern, and if the deflection was the lowest. Study of joint and suitable for the truss of 4 formed a affecting deflections low hot result showed that had the maximum tensive strength. Phai-Sang (Dendrocalamus membranaceus Munro) had the maximum appropriate for truss by the minimum deflection and the appropriate joint is bolt by Howe truss Appropriate and minimum deflection.