The ejection of a triatomic or diatomic hydrogen molecular ion from methanol (CH3OH and CD3OH) in intense laser fields (86 fs, 800 nm, approximate to 10(2)(14 W/cm)) is investigated based on the momentum vector distributions of the fragment ions measured by the mass-resolved momentum imaging technique. From the relative yield of D-3(+), HD2+, D-2(+) and HD+ ejected from CD3OH2+ and the anisotropic distributions of their momentum vectors, the rates of the formation of triatomic (13 and HD+) and diatomic (D-2(+) and HD+) fragment ions, k(t) = 0.15 ps(-1) and k(d) = 0.31 ps(-1), respectively, and the H/D exchange rate, k(ex) = 0. 13 ps(-1), are derived. (c) 2005 Elsevier B.V. All rights reserved.