Through sampling investigation of fouling organisms on the enhancement artificial reefs set up in Laizhou Bay, it was proved that oyster (Ostrea plicatula) was the dominant fouling species. Therefore the dry mass of shell (M_s), total fresh mass (M_t) and thickness (T) of oyster attached on the reefs were analyzed. The results showed that the M_t and M_s presented seasonal variation (P<0.01), that is, the values were the lowest in April and the highest in December. The reef age and the length of the time the enhancement reefs placed in the sea had significant effect on M_t, M_s and T. With the increment of reef ages, all indices increased obviously. The carbon sinks of oysters attaching to the tube enhancement reefs constructed in 2009, 2010 and 2011 in Laizhou Bay were 17.61, 16.33 and 10.45 kg·m^-3, respectively. The oysters on the enhancement reefs of Jincheng marine ranch with an area of 64.25 hm² had fixed carbon of 297.5 t C (equivalent to 1071 t of CO₂) from 2009 to 2013 in Laizhou Bay. To capture and store the same amount of CO₂ would cost about 1.6×10⁵-6.4×10⁵ US dollars. Therefore, oysters attaching to the enhancement reefs bring
about remarkable ecological benefits.