[Objective] Effects of rainfall on runoff and sediment in red soil region of Southern China were studied in runoff plots, to provide references for soil and water conservation engineering practice and fundamental research. [Methods] Based on three underlying surfaces (forest, agricultural land, bare land) of runoff plots in Mobu watershed of Yunnan Province, chrono-changes of rainfall, runoff, sediment and infiltration rate were observed from 2013 to 2015. Their relationships were analyzed by means of Mann-Kendall, grey correlation analysis and double cumulative curve, and so on. Meanwhile, effects of rainfall amount on runoff and sediment were studied. [Results] (1) The monthly rainfall during a year showed a fluctuated trend: firstly increased, and then decreased. The rainfall had no significant change among the three years. (2) Under same level of rainfall amount, significant difference in runoff among the three underlying surfac-runoff plots(p<0.05), they ranked as: forest > agricultural land > bare land. For runoff depth, it had the same rank. (3) Sediment yield had a strong correlation with rainfall and runoff. The correlative coefficients were 0.67~0.82 and 0.69~0.85 respectively. The sediment yield increased with the increase of rainfall intensity. Under similar rainfall scenario, forest had the minimum sediment, while bare land had the largest one. (4) The infiltration rate increased with the growth of rainfall and rainfall intensity in all three runoff plots. The infiltration rate was the biggest in forest with an average infiltration rate of 94.03%; the infiltration rate was the smallest in bare land, its infiltration rate was 86.28%. [Conclusion] As compared with agricultural land and bare land, forest plot increased soil infiltration capacity and reduced the runoff and sediment yield to some extent.