This paper describes the evaluation of three different walking patterns of a biped humanoid robot. Stretch-walking patterns with straight legs for a biped robot are compared with conventional walking patterns with bent legs in terms of energy consumption. This paper discusses walking pattern generation for various walks. To confirm the walking pattern evaluation, we have developed a biped robot, WABIAN-2/LL, whose leg mechanism differs from the conventional leg mechanism that has 3 DOF (degrees of freedom) in each ankle, 1 DOF in each knee, 3 DOF in each hip, and 2 DOF in the waist. Walking experiments are conducted with WABIAN-2/LL, and the results demonstrate that stretch walking patterns are effective in terms of energy consumption.