To investigate the long-term evolution law and mechanisms of soil moisture content in farmlands of Luancheng District in Shijiazhuang City, the Hurst indices and fractal dimension of soil moisture time series (2002 to 2008) at depths of 10 cm, 80 cm, and 150 cm were calculated by rescaled range analysis. Results show that the Hurst indices of soil moisture at 10cm, 80cm, and 150cm are 0.738, 0.877, and 0.953, respectively, all greater than 0.5, indicating some trends of variations of soil moisture at different depths; and the values of fractal dimension are 1.262, 1.123, and 1.047, respectively, indicating a decreasing trend of the fluctuation amplitude of soil moisture content with the increase of depth, which is consistent with the observed results.