The recently identified centrosome protein Nlp (ninein-like protein) is a key regulator in centrosome maturation, which contributes to chromosome segregation and cytokinesis. However, the mechanism(s) controlling Nlp expression remains largely unknown. Here, we show that Nlp expression is cell cycle dependent with a peak at G2/M transition in human cells. Nlp is a short-lived protein, and degraded by the proteasome via the anaphase-promoting cyclosome complex (APC/c) pathway. It interacts with the APC/c through the APC2 or Cdc27 subunits and is ubiquitinated. Following the treatment with proteasome inhibitors its protein level is elevated. Nlp binds in vivo to the degradation-targeting proteins Cdh1 and Cdc20, and overexpression of Cdh1 and Cdc20 enhances Nlp degradation. Using point mutations of the two putative degradation signals in Nlp, we have found that its degradation requires intact KEN box and D-box. Interestingly, the KEN-D-box-mutated Nlp exhibits much stronger capability of inducing anchorage-independent growth and multinuclei compared to the wild-type Nlp. Taken together, these findings indicate that Nlp expression is cell cycle dependent and regulated by APC-mediated protein degradation.