Bonding properties of Larch , Birch and Oak with aqueous polymer isocyanate adhesives were studied in this paper. First, effects of grain orientation of Larch s Birch and Oak on bonding properties were studied in this paper. The results showed that: dry compressing shear strength of quarter-sawn board of Larch was 1.41 times of flat-sawn board of Larch in normal conditions; wet compressing shear strength of quarter-sawn board of Larch was 0.29 times of flat-sawn board of Larch for repeatedly boil...