Abstract: With the development of commodity economy, it becomes more and more difficult or even unable to determine the socially necessary labor time, thus arising new definitions of the traditional economic terms concerning commodity value. Among them, the standard of value, as one of the functions of money, should be interpreted as the standard of price. And, due to the inability to prove that, by taking the society as a whole, and from a comparatively long period, the overall price of commodity is equivalent to its overall value, the exchange of equal value, as the law of value, should also be interpreted as the exchange of equal price. Actually, only the exchange value of commodity is its real value.

Key words: measure of value, exchange of equal value, socially necessary labor time