Abstract: Molt Inhibiting Hormone (MIH) is a neuropeptide member belonging to the eyestalk CHH family. It is a multifunctional protein, playing a major role in the molting activity of shrimp. MIH gene is one of the candidate genes for detecting polymorphisms associated with the growth traits. The present study was designed to investigate the effects of the MIH gene 3 exons on white shrimp growth traits. Primers for the 3 exons of MIH gene were designed from shrimp genomic sequences. Polymorphism was detected by DNA sequencing and the PCR-SSCP method was developed to genotype 340 samples.