The long term characteristics of mean added wave resistance (AWR) is very important from the view point of long term ship operation and ship design. Today, the short term prediction of AWR can be made through theoretical calculation. So, by using the long-term ocean wave data, we can carry out long term prediction of AWR. Here we carried out long term prediction, and found that the mean AWR follows the so called log-normal distribution. Furthermore, we investigated into the effect of wave data and ship form on that distribution. As wave data, we adopted the database of North Pacific Ocean by SRI and by BMT (GWS). As ship type, we adopted the bulk carrier with large B/d ratio.