In this study, the clam, pond water, and bait collected from the field were analyzed and showed that the number of original bacteria from the bait was lower than that in the pond and clam. The Vibrio spp. is still the main bacteria in the clam and pond water during the summer, among of theV. vulnificus, V. harveyi and V. parahaemolyticus. After long-term monitoring of various water quality environmental factors, it was found that from May to September, the average water temperature was between 28- 35 °C. The algae in the aquaculture ponds were dominated by the cyanobacteria, and the ratio up to 35-78%; The relative ammonia nitrogen values in the ponds were all above 0.8 ppm. It is shown that under high temperature environment, the clam be pressed for high temperature and cause the poor water quality. The competitive advantage of cyanobacteria is unfavorable for the growth of the beneficial nitrifying bacteria, which makes the clam limited to growth. The histopathology of the monitored clams revealed that the main pathogenic lesions of the clams were those around the intestinal tract and hepatopancreas, and the second lesions were found in the gill tissue of the clam. There was an acute inflammatory response causing gill epithelial cell proliferation. The inflammatory pathological found were also found around the cerebral - 1 - 1082299 1. 2. nerves or nerve nodes of some clams. Acute necrosis infiltration were also found in the muscle tissue. Most of the histological lesions could be related to the clinical symptoms of clams. At present, clam farmers mostly use probiotic control or disinfection strategies to improve environmental pathogenic bacteria or water quality environment, and through the good breeding management methods to prevent diseases.