This work is aim at studying the dependence of fission yields on incident neutron energy, so as to produce evaluated yield sets of the energy dependence. Experimental data at different neutron energies for gas fission products ^85m,87,88Kr and ¹³⁸Xe resulting from the ²³⁸U(n, f) reaction are processed using codes AVERAGE for weighed average and ZOTT for simultaneous evaluation. Energy dependence of the cumulative fission product yields on the incident neutron is presented. The evaluated curve of product yield is compared with the results calculated by the TALYS-0.64 code. The present evaluation is consistent with other main libraries in error permission. The fit curve of ^87,88Kr can be recommended to predict the unmeasured fission yields. Comparisons of the evaluated energy dependence curves with theoretical calculated results show that the predictions using purely theoretical model for the fission process are not sufficiently accurate and reliable for the calculations of the cumulative fission yields for the ²³⁸U(n,f).