An extensive program of laboratory model tests was undertaken to study the effect of slope on p-y curves due to surcharge load in dry sand. The paper concerns the method developed in a series of laboratory model tests to experimentally determine p-y curves. Bending moment curves are differentiated by using curve fitting method of cubic polynomial function. The study includes effect of slope angle and relative density on bending moment, lateral soil resistance, lateral deflection and non-dimensional p-y curves. The non-dimensional p-y curves for piles on sloping ground under surcharge load are developed modifying API RP 2A (2000) method by including a Reduction Factor (R) using the experimental results. Copyright© 2005-2009 National Institute of Informatics.