This paper is about the visualization of positive data subject to positivity constraint. It presents an algorithm that produces a non-negative graph through scattered positive data sets using Modified Quadratic Shepard method. The objective of positivity has been achieved by scaling of basis functions as far as it is necessary. This method is improved in that it produces the positive graph without much deviation of shapes from the ones due to Modified Quadratic Shepard scheme. The method is developed and implemented as a global scheme. Keywords Non-negativity, positivity, quadratic surface, shape preservation, constrained interpolation and scattered data.