Abstract: A shoe midsole has a heel portion provided with an elastic shock-absorbing member which is embedded therein and which has an arcuate projection, an air chamber, a plurality of cavities located in the peripheries of the arcuate projection, a plurality of first air ducts through which the cavities communicate with the air chamber, and a plurality of through holes extending from the top surface of the arcuate projection to communicate with the air chamber. The elastic shock-absorbing member further has a plurality of second air ducts extending inwards along the peripheries thereof to communicate with the cavities. The heel portion is provided with a plurality of recesses corresponding in location and number to the second air ducts.