Prostate cancer is threatening human health heavily, for its causes are related to diet, genetic factors, and lifestyle. Metal ions, which are necessary to our health, are important factors inducing many diseases including prostate cancer in the condition of absence or excess. Epidemiological and laboratory studies provide convincing evidence that green tea prevents and cures prostate cancer. Practically, interactions of catechins, which are the main bioactive components in green tea or GTP, with metal ions have a new aspect to investigate their mechanism in preventing and curing prostate cancer. In the present paper, we summarize some research about the effects of catechins with metal ions related to prostate cancer and their interactions on prostate cancer.