The streptococci pathogen is commomly founded in farmed fish. The bacterial disease causes serious mortality of marine fish, freshwater fish and brackish water fish, such as tilapia, sea bass, mullet, grouper and fourfinger threadfin. During high water temperature period, cases of infection are often found, causing serious losses to the aquaculture industry. This project intends to develop a rapid detection kit with simple, rapid, selective, high accuracy, high specificity and sensitivity which can be operated independently on the farm, detecting the number of common Streptococci in fish and environment , and can be used for quantitative analysis and drug sensitivity testing. By assessing the current risk index, monitoring the health of farmed fish and selecting the most suitable drug, it can achieve early prevention, reduce losses and lower the cost.