Abstract: The edible part of soft-shell lobster is much more than that of hard-shell lobster. To eat soft-shell lobster can help effective use of nutrients and reduce waste emissions. Soft-shell stage of lobster is prolonged mainly by rapid taking off shell and delaying hardening of new shell. Molting hormones added in diet can accelerate exuviation of lobster. Cooling can reduce metabolism rate of softshell lobster, which thus makes sure long-time constant hardness of shell.