Influenced by the global climate change, ocean waves in polar regions, especially in the Arctic Ocean, experienced significant changes over the past few decades, which resulted in strengthening wave-ice interactions in marginal ice zones. From the perspective of physical oceanography, this paper summarizes the present research situation of sea ice effects on ocean waves, discusses the attenuation of wave energy and the variations in wave dispersion relation based on both theories and measurements, analyzes the numerical simulation and the field observation of surface waves in ice-covered seas, and points out the main problems of modeling and forecasting ocean waves when sea ice exists. At last, the future research of ice effects on ocean waves is prospected. Generally, though the mechanisms of ice effects on waves are complicated and highly related to the sea ice types, the ice-induced wave attenuation shows an exponential relation with propagation distance, and the wave speed is influenced by sea ice more or less. In the near future, more wave observations under various types of sea ice covers are necessary to perform mechanism analysis, model validations and parameter calibrations, and then the high-accuracy operational wave forecast.