Abstract: To describe the osmosis pressure rule and the relationship between it and main effect factors, and to establish the cause and effect model for sea wall safety state real time monitoring, the monitoring data, including sea wall osmosis pressure survey data series, tidewater series and rain records, and their relationships were analyzed. Then, the frame of the cause and effect monitoring model was presented. The former tidewater factor of osmosis pressure was preselected by statistical distance analysis. A new rain effect factor that can reflect the rainfall amount and its duration was presented. These factors together with time effect factors were used to establish the osmosis pressure monitoring model with practical observed data.The results show that this kind model can be good at fitting and forecasting.