Abstract: Here is studied the distribution of hydrogen in the alpha phase and beta phase in the near alpha titanium alloy Ti-6Al-3Nb-2Zr-1Mo and the hydrogen distribution in the crack tip by using secondary ion mass spectroscopy(SIMS). It is found that when the mass concentration of hydrogen is below 100×10^-6, no hydrides are observed, and the content of hydrogen in beta phase is higher than that in alpha phase. Hydrogen is inclined to concentrate at the crack tip, and the size of the concentrated zone is a little smaller than that of the plastic deformation zone in the crack tip.