  In this paper, we explore the interrelationship between Eulerian numbers and
B splines. Specifically, using B splines, we give the explicit formulas of the
refined Eulerian numbers, and descents polynomials. Moreover, we prove that the
coefficients of descent polynomials $D_d^n(t)$ are log-concave. This paper also
provides a new approach to study Eulerian numbers and descent polynomials.
