Study on the effect of different soil and crop management practices on soil erosion and cassava yield was conducted on 8 percent slope of Map Bon soil series (Oxic Paleustults, fine loamy, mixed) at Sriracha Research Station. Eight management practices were selected to study and arranged in randomized complete block design with two replications. For the first experiment in 1988. The minimum soil lose was found on two plowing and two discings and intercropped with peanut plot while the maximum fresh root weight was observed on two plowings and two discings followed by up and down ridging plot. For the second experiment in 1989, The minimum soil loss was found on two plowings and two discings with contour bank plot and the maximum fresh root weight was also observed on the same practices. For the third experiment in 1990, The minimum soil loss was found on two plowings and two discings followed by contour ridging plot while the maximum fresh root weight was observed on no-tiled plot. From three year-study, it could be concluded that contour ridging and no-tilling are considered as better management practices for cassava cultivation on gentle slope sandy soil in the Eastern Region of Thailand. Higher soil loss and low cassava yield is found on unfertilized plot.