We build the complete supersymmetric version of a 3-3-1 gauge model using the
superfield formalism. We point out that a discrete symmetry, similar to the
R-symmetry in the minimal supersymmetric standard model, is possible to be
defined in this model. Hence we have both R-conserving and R-violating
possibilities. Analysis of the mass spectrum of the neutral real scalar fields
shown that in this model the lightest scalar Higgs has a mass upper limit, and
at the tree level it is 124.5 GeV for a given illustrative set of parameters.Comment: RevTex, extended and revised version, 20 pages, one eps figur