Contact resistance is an important index for characterization of contact performance. The chaotic characteristics of contact resistance time series for the detected contacts are identified and predicted. The minimum embedding dimension of contact resistance time series is determined by Cao method. It proves that the contact resistance time series has the chaos characteristics by drawing phase diagram method and calculating largest Lyapunov exponent from qualitative and quantitative view respectively. The chaos prediction and the reliable scope for partial data of contact resistance time series are presented based on the Largest Lyapunov exponent. The result indicates that the prediction accuracy is higher and steadier within the predictable range than beyond of it.