In this study, we first show that the system of Frenet-like differential equation characterizing spacelike curves of constant breadth is equivalent to a third order, linear, differential equation with variable coefficients. Then, by using a rational approximation based on Bernstein polynomials, we obtain the set of solution of the mentioned differential equation under the given initial conditions. Furthermore, we discuss that the obtained results are useable to determine spacelike curves of constant breadth in Minkowski 3-space E 3 1 .In this section, we establish differential equations characterizing the spacelike curves of constant breadth. This study is based on the concepts presented by Köse [10,11] and Sezer [16,17] for space curves of constant breadth.