The effect of gait parameters such as step length and walking speed on the traction coefficient and the slip between a shoe sole and a walkway was clarified experimentally, and desirable gait to reduce the chance of slipping was also suggested. The maximum peak value of traction coefficient obtained at heel-strike period |F_h/F_n|_h and that at toe-off period |F_h/F_n|_t increased with an increase of step length irrespective of subjects when walking on dry walkway. Meanwhile, |F_h/F_n|_h or |F_h/F_n|_t slightly decreased or took almost constant value with respect to walking speed. Based on the results of gait experiments on glycerin-lubricated walkway, it was clarified that a walk with a shorter step length and a higher walking speed was effective for prevention of slip irrespective of subjects, and such a gait provided a shorter slip distance. The reason why the smaller maximum peak values of traction coefficient can be obtained in case of walking with a shorter step length and a higher walking speed was discussed based on the kinematic analysis using the body center of mass (COM) and center of pressure of shoe sole (COP).