Tau threshold experiments: status and expectations

A study of the threshold behavior of the cross section of τ lepton production is the most promising way of the τ mass determination. The most precise measurement of this kind was performed by the BES collaboration in 1991. We critically analyze the results of this experiment and report the main features of the new one, planned with the KEDR detector at the VEPP-4M collider in Novosibirsk.