It is predicted by calculations that a tritium breeding ratio (TBR) greater than 1.2 may be obtained by a full-coverage blanket of Pb (10 cm), natural-Li (40 cm) and a graphite reflector (30 cm), however with about 8% uncertainties among the used nuclear data sets from different evaluated files. To check this, an integral neutronics benchmark experiment was carried out using a Pb-Li-C slab module. From comparisons of measured 93Nb(n,2n), 115In(n,n′) and 6Li(n,t) reaction rates with those obtained by calculations, the following conclusions were obtained: (1) a TBR greater than 1.3 can be obtained with the full-coverage Pb-Li-C blanket; and (2) the data set of ENDF/B-IV (Pb) + JENDL-3T (Li and C) has given the best agreement, among currently available evaluated data files, for 6Li(n,t) reaction rates, though about an 5% underestimation is observed.