The mixing performance of reciprocal shake mixing was extremely different from that of rotationally shake mixing. The mixing time did not decrease monotonously with increasing the shaking frequency. The transition of a flow pattern from a progressive wave type to a rotational wave type was quite complicated. The frequency, at which the steady rotational now gives the optimum operation for mixing, is directly proportional to the natural frequency of the cylindrical vessel. This frequency can also be correlated only with the Froude number, and it did not depend on the shaking width. The mixing time decreased monotonously with increasing the power consumption per unit volume.