PURPOSE: To obtain a highly stable liquid oil having both softening stability and cooling stability at a low cost, by carrying out ester interchange of a slightly hydrogenated vegetable oil having a specific iodine value with a laurine based fat or oil.

CONSTITUTION: 60W99wt%, preferably 65W95wt% slightly hydrogenated vegetable oil having 80W95 iodine value, e.g. obtained by slightly hydrogenating a vegetable oil such as rapeseed oil or soybean oil by the conventional method is subjected to ester interchange with 1W40wt% preferably 5W35wt% laurine based fat or oil, e.g. coconut oil or palm kernel oil, by the conventional method, and an additive, e.g. emulsifying agent or antioxidant, is added, as desired, to the resultant ester interchange product.