One color two-photon 3(3)Sigma(+)(g) <- [b(3)Pi(u) similar to A(1)Sigma(+)(u)] <- X-1 Sigma(+)(g) transitions of Cs-2 observed earlier [9] have been assigned: the upper state levels span the range of the vibrational and rotational quantum numbers v = 2 similar to 9 and N = 25 similar to 248. The potential function of the 3(3)Sigma(+)(g) state in a version of a deformed ab initio potential has been determined from the term values of these levels. The reliability of this potential is confirmed by simulations of the spectra of resolved fluorescence and by comparing with the Rydberg-Klein-Rees potential obtained from an alternative set of data in [13]. (C) 2012 Elsevier B.V. All rights reserved.