For the first time, this paper reports the variations of contents of noxious elements from sediments in the lakes of Fujian Province. Based on the study of environmental geological evolution of the sedimentary column since more than 40 years ago in Longhu Lake, Jinjiang City, it was found that the pollution degree was increased sharply during 1976~2002. Seven elements, i.e. Cd,Hg, As,Pb,Cu,Zn and Cr were increased the fastest, especially Cu, the pollution process of which can be divided into three phases: A (1976~1984), slight pollution; B (1984~1993), weak pollution and C (1993~2002), serious pollution. The pollution degree of period B is 1.3 times as high as that of period A, and the pollution degree of period C is 3.5 times as high as that of period A. This indicates that the pollution degree has increased tremendously. In April, 2002, the concentrations of Hg, As and Pb, violently poisonous elements in surface sediments of Longhu Lake, were respectively 46.3 times (Hg), 3.3 times (As) and 1.9 times (Pb) as high as the lowest corresponding values in period A (1976~1984), and exceed enormously its "Warnine Line" (for example, Hg is 4.4 times as high as that of the standard value). Increasingly deterioration of environmental geological conditions in Longhu Lake not only influence human body's health (for instance, the incidence of cancer will be increased sharply), but also warn us of the possibility of reappearance of the Japanese "Minamata Disease" in this region.