The present invention relates to a shock-absorbing insole for a footwear and a method of manufacturing the same wherein the shock-absorbing insole is disposed on the bottom surface in a footwear for absorbing and reducing the shocks applied from the ground to a wearer's sole during running, jogging, walking, etc. The shock-absorbing insole includes: a bottom plate made of a synthetic resin and having fabric attached on the top surface thereof; and a shock-absorbing member made of an elastic synthetic resin for absorbing shocks applied to the footwear in such a manner as to be contracted and restored from/to its original state in accordance with the load applied during walking, the shock-absorbing member being formed integrally with a bottom surface of a heel portion of the bottom plate.