The invention relates to 2-methylene-5-substituted-methylenecyclopentanone derivatives of formula I, and the use thereof. The derivatives of formula I as active components are useful for preparing a medicine for the treatment and/or prevention of cancer diseases such as breast cancer, lung cancer, colon cancer, rectal cancer, stomach cancer, prostate cancer, bladder cancer, uterus cancer, pancreatic cancer and ovary cancer. The active compounds of the invention may be used as an anticancer drug alone or used in combination with one or more other antitumor drugs. A combined therapy can be carried out by administrating each therapeutic component concurrently, subsequently or separately.