An equationon the formation rate of R11 hydrate in water and aqueous alcohol solutions is derived on basis of a dispersed liquid interface reaction model. From the equation, the relation between percent conversion(β) of R11 and elapse time (θ) is obtained by; −(1⁄m)ln(1-β)=kAΔTⁿθ where, m is conversion coefficient (R11 in hydrate⁄hydrate = 0.3095), k is over-all coefficient of mass trnsfer [kg⁄m²h°C], A is surface area of dispersed liquid (R11) [m²⁄kg], and ΔT is supercooling degree [°C]. Using above equation, the experimental date of the previous paper are analyzed, and it is found that these date are well applied to the equation. From these results, it can be considered that the formation rate of R11 hydrate in water and the aqueous solutions of ethanol (3.6% and 10%), n-propanol(0.9%) and n-butanol(1.9%) is principally governed by the dispersed liquid interface reaction, not by the crystal growth of R11 hydrate.