PURPOSE: To provide an additive for grease which improves adhesiveness and extreme-pressure characteristics of grease and has spattering preventive and sound deadening effects, prepd. by mixing MoS2 into an intermediate compsn. of thermal cracking of aromatic hydrocarbon compd.

CONSTITUTION: The additive is prepd. by mixing MoS2 into an intermediate compsn. of thermal cracking of aromatic hydrocarbon compd. (e.g. incompletely carbonized tar pitch or asphalt obtained by heat treatment of aromatic hydrocarbon resin and aromatic hydrocarbon oil). The additive shows good dissolution in grease and improves adhesiveness and extreme pressure properties of grease. When the grease is applied to the surface of metal or plastic, adhesive lubricating substances are adsorbed exhibiting improved lubrication and excellent sound deadening effect which are not obtainable when MoS2 is merely added to a grease. When used for lubrication of low-speed rotating gear such as automobile gear box and transmission and control device such as switch, marked effects are observed in prevention of spattering of grease and noise reduction.