The research was conducted on mahogany (Swietenia macrophylla King.) plantations at 2, 5 and 9 years old located in RPH Getas, BKPH Monggot, KPH Gundih, Central Java. This study was carried out to determine the condition of vegetation communities of mahogany stand on several phases of age and its potential in controlling runoff and erosion. Two observation plots including runoff and erosion were set up by the size of 22.1 m x 4 m per plot. Two plots of the same size were also set up on open land (without plants) as a control. Observation of vegetation was also carried out in the plot observations of erosion. This study revealed that the erosion and the runoff surface of mahogany stand controlled by the presence of litter and undergrowth. The level of erosion of mahogany at 2, 5 and 9 years old declined respectively from 49.4, 15.3 and 8.7% compared to the control (soil without plants). The runoff coefficient value which showing the water runoff in stands of mahogany age of 2, 5 and 9 years were: 0.24 (4% from the control), 0.19 (24% from the control) and 0.14 (44% from the control). The selection activities in tree breeding will improve seed mahogany therefore, can increase the wood production (biomass) and decrease the runoff and erosion.