The full-length cDNA of 14-3-3ζ gene were cloned from Apostichopus japonicus. The expression profiles of miR-137 and Aj14-3-3ζ were investigated in bacterial-challenged sea cucumber and LPS-exposed cultured coelomocytes. miR-137 could modulate Aj14-3-3ζ expression at protein level. Coelomocytes apoptosis was significantly promoted in Aj14-3-3ζ knock-down and miR-137 inhibited sea cucumber.