The representative semi-empirical sea clutter models (the GIT model and the TSC model) are not ideal applicability in littoral environments. In order to develop a really meaningful sea clutter model, relationship between sea clutter and parameters of sea conditions need to be studied. The wave height is a major influencing factor among these parameters of sea conditions. In this paper, experimental data of L-Band small-grazing-angle sea clutter were used to study the relationship between sea clutter and wave height. The parameters of relationship between wave height and sea clutter are obtained. These work play an important role in establishment of L-Band small-grazing-angle sea clutter model in littoral environment.