Intal solitary waves(ISWs)always happen in marginal seas,where stable stratifi cation exists.ISWs may carry large energy when they propagate and affect marine engineering constructions such as marine drilling platforms.Previous studies,including a large number of mooring observations and laboratory experiments,show the speed of ISWs will change when they pass by shelf slopes.Korteweg-de Vries(KdV)theory explain this phenomenon.In the paper,we use a laboratory experiment and a numerical model experiment to verify this theory.In the laboratory experiment,we injected two layers of water of different densities in a tank to simulate marine stratifi cation and make ISWs.We use a CCD camera to record the whole process.The camera can take 16 photos per second.In the numerical experiment,we input the same original conditions as the laboratory one.The results of 18 different original conditions show the dimensionless factor δ plays a key role in deciding the amplitudes and shapes of ISWs.The main conclusion also contains that small-amplitude waves match well with KdV theory while mKdV is better for large-amplitude waves.Whether the laboratory experiment or numerical experiment shows results with a high agreement.In future studies,we may use a numerical model with higher resolution to get analysis about phase speed and energy of ISWs.