We presented a Chandra observation of the HII region RCW 89 in Dec 2004. RCW 89 is part of the radio shell supernova remnant MSH 15-52 which contains a 150 ms young pulsar PSR B1509-58. Comparing with the X-ray image taken by Chandra in Aug 2000, we found that each plasma clouds in RCW 89 have moved outward from the SNR center. The velocity of the radial motion is 5800 ± 2300 km s-1. This result agrees with the scenario in which the plasma clouds in RCW 89 are the SN ejecta from the progenitor of the pulsar.