Topological conformal field theories based on superconformal current a
lgebras are constructed. The models thus obtained are the supersymmetr
ic version of the G/G coset theories. Their topological conformal alge
bra is generated by operators of dimensions 1, 2 and 3 and can be rega
rded as an extension of the twisted N = 2 superconformal algebra. Thes
e models possess an extended supersymmetry whose generators are exact
in the topological BRST cohomology.