Hormetic effects on the growth were found in the roots of rice (Oryza sativa L. cv. Shengdao 16) exposed to increasing concentrations of La 3+ (0.05, 0.1, 0.5, 1.0, and 1.5 mmol/L). The results indicated that La 3+ promoted the growth of rice roots at 0.05 mmol/L, but inhibited the growth at 1.0 and 1.5 mmol/L La 3+ after 13 days of exposure. Transmission electron microscope showed that La 3+ was mainly deposited in the cell walls of the roots. In addition, the accumulation of K, Mg, Ca, Na, Fe, Mn, Zn, Cu, and Mo in the roots was also affected with the exposure of different La 3+ treatments. It showed that La 3+ affected the nutritional status of roots and further regulated the growth of rice.