The most produced tank, might be the former Soviet (Russian) tank T54/55. There were nearly 100,000 of them produced, a figure that might include the Red Chinese version, the T-59; mainly used for export. Considering that over 50,000 Soviet (Russian) T-34's were produced (WW2 tank), and T62's, T64's, T-72's, etc. The former Soviet Union might very well still have over 100,000 tanks in it's inventory.