Abstract��The resource of Coelomactra antiquata was investigated in Changle coastal waters in October 2012. 9 samples were collected at only 4 investigation sites, accounting for 12.9% of the all sites. The shell length of the samples is 27.11mm��113.55mm, average of 61.29mm; the body weight is 2.0g��162.0g, average of 41.8g. The maximum value of distribution density and biomass of Coelomactra antiquata was 144.30 ind./hm2 and 4.98kg/hm2 respectively. The results show that the resource of Coelomactra antiquate in Changle coastal waters was declined obviously.