Abstract: In order to explore the changes of dissolved oxygen and pH value in shrimp ditches and its effect on crayfish production in shrimprice co-cropping,a shrimp-rice co-cropping field is carried out in the shrimp-rice co-cropping field in Yajiao Village,Hubei Province.The experiment took the shrimp-rice symbiosis period from July to September in 2019 and 2020 as the main observation period,and monitored the dissolved oxygen content and pH value of the shrimp ditch in 9 shrimp paddy fields. Through the experiment,it is concluded that the dissolved oxygen contents in the shrimp-rice co-cropping field is related to the aquatic plants in the shrimp ditch,rainfall,and artificial treatment measures. Excessive duckweed in shrimp ditches and long-lasting heavy rain will reduce the dissolved oxygen contents in shrimp ditches. The production of crayfish is positively correlated with the contents of dissolved oxygen as a whole. When the dissolved oxygen is lower than 2 mg/L,the production of crayfish will decrease significantly. The pH value in the shrimp ditch generally varies between 7.3～8.4,and the average pH value of the shrimp ditch in 2020 is lower than in 2019. By comparing the yields,when the pH fluctuates around 7.7,the average yield of crayfish is at a relatively high level.