Abstract: Research on the main profit indicators of large and medium-sized industrial enterprises using the LMDI numerical decomposition method shows that from 2001 to 2020,market size was the most important factor driving profit growth,followed by the operating efficiency factor,and changes in the industry structure had little impact.Looking from the four periods of 2006/2001,2011/2006,2016/2012 and 2020/2016,the market size effect continued to decline after reaching the maximum positive effect in the second period,and showed a negative effect in the fourth period.The operating benefit factor showed a stable positive effect in the first two periods,and became the only positive effect factor in the fourth period after turning into a negative effect in the third period.The industry structure factors showed positive effects in the first three periods and negative in the 4th period,but the effects were small.Therefore,to promote the sustained and high-quality growth of the main profits of industrial enterprises,we should pay attention to stabilizing and expanding market demand,especially the scale of domestic demand.We should encourage industrial enterprises to make profits by taking advantage of scientific and technological progress,and speed up the transformation of the industry structure to the structure with advanced manufacturing as the main body.

Key words: industrial enterprise, profit, market scale effect, industry structure