arXiv:1002.3505v3 [cond-mat.quant-gas] 26 Aug 2010 a) Corresponding author e-mail : abc.anindya@gmail.com 1 We study the ground state pair-correlation properties of a weakly interacting trapped Bose gas in three dimension by using a correlated many-body method. Use of the van der Waals interaction potential and an external trapping potential shows real- istic features. We also test the validity of shape-independent approximation in the calculation of correlation properties. PACS numbers: 03.75.Hh, 03.65.Ge, 03.75.Nt Anindya Biswas 1 , a) , Barnali Chakrabarti 2 , 3 and Tapan Kumar Das 1 1 $^{1}$Department of Physics, University of Calcutta, 92 A.P.C. Road, Kolkata 700009, India $^{2}$The Abdus Salam International Centre for Theoretical Physics, 34100, Trieste, Italy $^{3}$Department of Physics, Lady Brabourne College, P-1/2 Suhrawardy Avenue, Kolkata 700017, India Pair-correlation properties and momentum distribution of finite number of interacting trapped bosons in three dimension