Selection of descent direction at a point plays an important role in numerical optimizationfor minimizing a real valued function. In this article, a descent sequence is generated for the functions with bounded parameters to obtain a critical point. First, sufficient condition for the existence of descent direction is studied for this function and then a set of descent directions at a point is determined using linear expansion. Using these results a descent sequence of intervals is generated and critical point is characterized. This theoretical development is justified with numerical example.keywords Line search technique, Markov difference, Interval ordering, Descent direction, Critical point.