Abstract: Shellfish are generally cultured in open sea areas, which makes it difficult to carry out shellfish disease prevention and control. Therefore, investigating the epidemic infection law of pathogens is particularly important for the occurrence, development and control of shellfish pathogens. In this paper, we applied common PCR (Polymerase Chain Reaction) technology to investigate the seasonal dynamics and spatio-temporal distribution of Perkinsus spp. among five mainly cultivated shellfish in the six aquaculture locations along the coastal area of Guangdong Province. Two Perkinsus spp. were detected (P. beihaiensis and P. olseni). The prevalence of P. beihaiensis was significantly higher than that of P. olseni. Among the five sampled shellfish species except Crassostrea angulate, all were infected by Perkinsus spp., and C. hongkongensis and Haliotis diversicolor were infected by two Perkinsus spp., while Pinctada martensii and Chlamys nobilis were only infected by P. olseni. The prevalence of Perkinsus spp. in western Guangdong, including Zhanjiang, Yangjiang and Jiangmen was 17.17%, significantly higher than that in eastern Guangdong, including Shanwei, Jieyang and Shantou. The prevalence of Perkinsus spp. in summer and autumn was 15.67%, significantly higher than that in winter and spring. In different coastal areas, the seasonal occurrence variation of Perkinsus spp. might be affected by the host's culture environment, cultivated mode, feeding type, living type and other comprehensive factors.