[en] A criticism is presented on attempts to synthesise superheavy elements by heavy-ion reactions. In particular a detailed discussion is made on the fusion reactions tried to produce superheavy elements so far. It is emphasised that our present knowledge is rather poor to predict a law of competition between fusion-fission and fusion-evaporation. An existance of upper limited angular momentum J sub(ER), at which the evaporation is dominant, is suggested. Furthermore it is shown that a future experimental and theoretical study of J sub(ER) will be essential to predict the cross section for synthesising superheavy elements quantitatively. (author)