In order to locate hydrogen dissolved in metals a channelling method utilizing a nuclear reaction ¹H(¹¹B, α) αα with a ¹¹B beam has been developed. This method has been applied to study the effect of metallic solutes on the state of hydrogen in metals. The lattice location of hydrogen in Nb-based Nb-Mo alloys with different concentrations (C_Mo) of undersized Mo atoms of 3, 10, 20 and 26 at% has hitherto been investigated. These results are summarized in this paper and the interaction of hydrogen with metal solutes is discussed. At low Mo concentrations less than 10 at% hydrogen is trapped by Mo atoms at room temperature due to attractive interaction to be located at sites displaced from tetrahedral (T) sites by about 0.6 Å toward the nearest neighbour Mo atom. In the case of C_Mo=3 at%, hydrogen is detrapped at 373 K and enter a T site. The number of H atoms trapped by one Mo atom is limited. It is 0.7-1.0 for C_Mo=3 at% and decreases with increasing C_Mo. The excess H atoms are located at T sites. For C_Mo=20 at% such trapped site occupancy is not observed, and 70-80% of the H atoms are located at T sites and the rest are at octahedral (O) sites at low H concentrations. For C_Mo=26 at%, most of the H atoms are located at T sites.