is a important parasite of marine crustacean. detection system was developed by using the loop-mediated isothermal amplification (LAMP) method. A set of four primers including two outer primers and two inner primers, were designed from DNA extracted from infected crabs under constant temperature of 65 The amplification products were detected visually by ovserving whether white deposition comes into being or using SYBR green I dye, which turns green in the presence of amplified products and remains orange in its absence, or by electrophoresis. The assay was found to be 10⁴ fold more sensitive than PCR assay. A comparison between LAMP and PCR assay using 25 clinical samples showed good correlation. The developed LAMP assay is simple, rapid, cost-effective, specific and highly sensitive for disease detection.