  Recently, it has been shown that the minimum number of gauge invariant
couplings for $B$-field, metric and dilaton at order $\alpha'^3$ is 872. These
couplings, in a particular scheme, appear in 55 different structures. In this
paper, up to an overall factor, we fix all parameters in type II supertirng
theories by requiring the reduction of the couplings on a circle to be
invariant under T-duality transformations. We find that there are 445 non-zero
couplings which appear in 15 different structures. The couplings are fully
consistent with the partial couplings that have been found in the literature by
the four-point S-matrix element and by the non-linear Sigma model methods.
