Abstract: Based on the study of the characteristics of grain sizes of the sediments in Fuxian Lake, the following are analyzed and explored: grain-size index, variation characteristics of fractal dimension and their correlation of lacustrine deposits; environmental significance of grain-size fractal dimension of deep lake sediments. The results show that the sediments of Fuxian Lake are mainly composed of silt and clayey silt, respectively accounting for 14.71% and 85.29%. There exist the features of poor sorting, negative skewness and narrow kurtosis in the lake sediments, and the varied range of lake grain-size was small, from 7.10 to 8.45 μm, with an average of 7.76 μm. The fractal dimension of sediments ranges between 1.81 and 2.76, with an average of 2.36. The correlation coefficient (R) between the fractal dimension and the other parameters (e.g. average particle sizes, sorting coefficients and kurtosis) is 0.94—0.99, which exhibits the significant fractal features of distribution of grain size sediments in Fuxian Lake. Meanwhile, there exists significant positive correlation between fractal dimension of sediments and average grain-size, sorting coefficient, and kurtosis; this positive correlation indicates that the change of the transport capacity and the sedimentary environment of the lake catchment, and the fractal dimension of the grain-size could be considered as a sensible means to study regional environmental change. By comparing the records of human activities in Fuxian Lake catchment during the past 1700 years, it indicates that the extreme values of fractal dimension in lake sediments correctly recorded the frequent human activities in the catchment. Therefore, the application of fractal research in deep-water lakes will provide scientific basis for further study of environmental attributes of regional sediments.