Acacia nilotica. L commonly known as babul, kikar or Indian gum Arabic tree, has been recognized worldwide as a multipurpose tree. Set of experiments were conducted  for  evaluation of the allopathic effects of water extracts of  different parts (park, leaves and pods)  of  A. nilotica as well as  soil extracts  under canopy on seed germination and  seedling  development of  receptor specie (Cucumus sativus L.) under different concentration (1%, 5% and 10% ).  Inhibitory effect of the different donor plant parts water extracts was ranked as follows: pod > leaf > bark. Soil extracts at different distances from trunk had stimulatory effect at 2m and 5 m distance while at the edge showed inhibitory effects on seed germination and seedling development of both C. sativus L.