In order to dehydrate and protect the three ancient boats unearthed from Xiaohai, the water - city of Penglai in 2005, the salts concentration of the wood boats silt nearby and (sea and ground) water samples, which were collected from boat No. 2 and boat No. 3, were analyzed in Shandong Provincial Analytical Test Centre. The analysis results show that the salts concentration in both wood and silt is higher than that in water. The more severely the wood rotted, the higher the salts concentration in wood is. The data and methods of the investigation results will contribute much to the further conservation treatment.