With published solubility data of hydrogen in the α-phase of binary alloys of zirconium with niobium, titanium, hafnium, yttrium indium, lead, antimony and oxygen at 750℃, the interaction parameter of each alloying element is calculated at the temperature up to 5 atomic percent of alloying elements. The terminal solubility of hydrogen in the α-phase of multicomponent alloys of zirconium has been predicted by means of interaction parameter. The temperature dependence of the interaction parameter of oxygen is calculated at the temperature range of 650℃-800℃. Interaction parameter of niobium in β-phase has been also calculated as function of temperature.