In the aim of studying the growth and distribution of bamboo root(stem) system and its protection effect on slope, a 5-year investigation on ecological protection by bamboo was carried out in a village at Bijie City from 2012 to 2016. Field digging and dynamic monitoring technique were used in the area for the investigation. Results showed that 1) biomass of bamboo root(stem) system increased year by year after bamboo planting, and biomass increase of rhizomes was faster than that of root system; 2) in horizontal and vertical directions, the length of bamboo root system gradually increased, but the increasing rate alleviated over years, and the root(stem) system reached canopy in 2015-2016; 3) at the beginning, protection effect of bamboo on the slope was not obvious, then the average downward displacement of landslide body along the slope gradually decreased and showed a stable tendency in 2015-2016. In conclusion, the slope protection effect of bamboo greatly improved with the increase of planting age and the growth of root system, for the landslide body tended to be stable in 2015-2016. The results could be taken as reference for landslide treatment in similar areas.