The blood clam Tegillarca granosa selectively accumulates Cd from many metal ions in the marine environment. Moreover, the clams show strong tolerance to cadmium. To explore the molecular mechanism of Tegillarca granosa selective enrichment of Cd, we choose Cu2+ exposure group as the positive control,the natural seawater group as the negative control,and Cd2+ exposure group as experiment group. After exposure, the gill transcriptome of Tegillarca granosa was constructed.