PURPOSE: To obtain a primary or secondary allyl alcohol in high conversion and selectivity, by the isomerization of a tertiary allyl alcohol in the presence of a specific catalyst active for a long term and stable to high temperatures.

CONSTITUTION: A tertiary allyl alcohol expressed by formula I (R1 is lower hydrocarbon group; R2 is hydrocarbon group or R1 and R2 together represent cyclic group; R3 is H or hydrocarbon group), e.g. 1-methyl-cyclohexanol or 1-vinyl-3,3- dimethyl-cyclohexanol as a starting material is isomerized in the presence of a catalyst expressed by formula II [L is hydrocarbon group; R is L or Ge(L)3; m is 1, 2 or 3; n is 0, 1 or 2, and the total of m and n is 3], e.g. tris-(trimethylgermanoxy)-vanadium oxide, preferably at 100W250°C, to give the compound expressed by formula III.