Since 1970, the Port and Harbour Research Institute has been cooperating with the Bureau of Ports and Harbours, Ministry of Transport, and its associated agencies to carry out the coastal wave observation at their network stations. 　The P.H.R.I. processed and analyzed the wave records obtained at these stations, and has been publishing the wave statistics in a series of reports. The title of the reports are Annual report on wave properties at the network stations and Wave statistics in the coastal wace observation network for 3-year, 5-year and 10-year data. 　This Technical Note is the version arranged for 15-year data of the series, which covers the wave data obtained up to 1984 at 34 wave observation stations, where the observation has been carried out more than 3 years. 　The wave statistics at each station are summerized in the following forms: 1)The mean and the maximum significant waves for each month, season and year. 2)The joint distribution of the significant wave heights and periods. 3)The persistance of sea states. 4)The correlations between various wave parameters. 5)The all-time high significant waves and maximum waves recorded at each station since the obsercation started. 6)The wave spectra at some severe storms. 7)The wave characteristics around Japan during some extreme sea states.