Molting in decapod crustaceans is coordinated by endocrine cues,and the primary axis of endocrine regulation comprises a steroid-producing epithelioid gland termed the Y-organ (YO) and a neurosecretory center termed the X-organ /sinus gland complex ( XO /SG). The signaling pathway activated by MIH,however, remains a controversy. This paper has summarized cellular mechanisms of the MIH regulation,including research methods and current three controversial issues: MIH receptors,functions of cAMP and cGMP,and functions of Ca²⁺ .