In this research, green synthesis of silver nanoparticles using elaeis guineensis leaves extract was investigated and the effect of reaction time in reduction mechanism and particle size is studied. UV-visible sprectrophotometer was used to monitored the reduction reaction of silver ions to silver nanoparticles and formation of silver nanoparticles shown at 15 minutes. Transmission electron microscopy (TEM) and field emission scanning electron microcopy (FESEM) shows polydispersed and irregular shape of silver nanoparticles with aggregation. Further confirms the formation of silver nanoparticles by energy dispersive x-ray analysis (EDAX). From this research, it was found that the increasing reaction time increases the rate of reduction reaction of silver ions.