Abstract: Loss   of  [Als] and [Si]   and   change   of   inclusions   in   low   alloy   steel (electrode-0.030%[Als],0.29% [Si],20×10^-6 T[O]) remelted   by   a   15   kg   electroslag   remelting (ESR)furnace   with   CaF₂-Al₂O₃-CaO-SiO₂   slag   system  in argon atmosphere with argon flow rate 25 L/min and in air atmosphere have been studied. Results showed that remelted in   air   atmosphere, T[O]   of  ESR   ingot   increased   to   36×10^-6, while [Als]  and [Si] decreased respectively   to   0.011%  and    0. 17%;remelted    in    argon    atmosphere, T[O]    of    ESR    ingot    was    24×10^-6,[Als] and [Si]    were    respectively 0.024%  and  0.28%.As  compared  with  that  remelted  in  air  atmosphere, the  size  of inclusions  in  ingot  remelted  in  argon atmosphere was minor and the distribution of inclusions was more homogeneous and dispersed.