Efficient long-term cell tracing in a noninvasive and real-time manner is of great importance to understand genesis, development, invasion, and metastasis of cancerous cells. Cell penetrating organic dots with aggregation- induced emission (AIE) characteristics are successfully developed as long-term cell trackers. The AIE dots enjoy the advantages of high emission efficiency, large Stokes shift, good biocompatibility, and high photostability, which ensure their good performance in long-term non-invasive in vitro cell tracing. Moreover, it is the first report that AIE dots exhibit certain permeability to cellular nucleus, making them attractive potential candidates for nucleus imaging. The AIE dots display superior performance compared to their counterparts of inorganic quantum dots, opening a new avenue in the development of fluorescent probes for monitoring biological processes.