In tread brake of freight cars, brake force is produced by the friction between the wheel and the brake shoe. Friction coefficients associated with the brake power, weight variation and brake shoe types should be sensitively treated as the design parameters. The conditions of the car, empty and loaded, should also be taken into consideration in brake force design and the control of brake force has some limitations in terms of the brake system design so that the brake friction materials selection should be considered as important measures to solve that difficulties. Friction characteristics of brake friction materials should remain within the range of maximum and minimum value and the friction performance should remain stable regardless of brake time and temperature. This study presented an experimental evaluation method to secure optimum brake performance by keeping safe brake effect and brake distance by the friction coefficient of the brake shoe of the freight cars.