Hard-to-treat cancers are closely relative to uncontrolled cell proliferation, invasion, and metastasis. Assessing proliferation and invasion properties of tumor cells both in vitro and in vivo is especially important for acquiring reliable information for cancer pathogenesis, drug screening, and therapeutic effect evaluation. Herein, we developed a multicolor fluorescent nanoprobe for simultaneously monitoring breast cancer cells' proliferation marker Ki-67 and invasion marker urokinase plasminogen activator (uPA). After treated with the anticancer drugs tamoxifen and curcumin, the changes in cancer cell proliferation and invasion properties were visually detected and therapeutic effects of corresponding drugs were further assessed in vitro and in vivo. The design of the fluorescent nanoprobe opens up an avenue for investigating unscheduled proliferation, invasion, and metastasis in living cells and in vivo and as such will be a promising tool to screen antitumor drugs and evaluate drug efficiency in an extremely efficient manner.