Brand extension, as a vital part of brand strategy, is chosen by more and more Chinese corporations as a way to expand market and make use of brand asset. However, many cases of both unsuccessful and successful use of brand extension force people to reevaluate brand extension strategy. Based on the studies on brand extension theory in the world, this paper tries to analyze the latest market trend and reevaluate the strategy of brand extensions from the angle of brand core value. Finally, it draws the conclusion that brand extension should aim at upgrading and strengthening brand core value.