An important aspect of agriculture green development is to realize zero growth of chemical fertilizers and reducethe environmental problems caused by excessive and unreasonable application of chemialfertilizer.InChina，the resourcesof organic fertilizers and straw are huge andunderutilized，and the application of organic fertilizer and straw returning to the feild after the reduction of chemical fertilizer application has become one of the main management measures to achievezero growth of chemical fertilizer，and has received more and more attention in recentyears.However，the responseof crop yield to short-term fertilizer reduction and its driving factors remain unclear and require forther study.A 6 -yearfield experiment(2010～2016)carried out in the North China plain，a typical winter wheat -summer maize platingarea，the effects of reducing chemical fertilizer application and applying reduce organic fertilizer and straw on maize yield，soilfertility，soil pH and enzymeactivity.There were fourtreatments:nofertilizer(CK)，100% chemical fertilizer(NPK)，70% chemical fertilizer +30% organicfertilizer(NPKM)，and 70% chemical fertilizer + 30% organic fertilizer +straw(NPKMS).The results showed that fertilization treatment significantly increased maize yield compared withCK，and NPKMS significantly increased by 8.3% compared withNPK.Compared withNPK，NPKM did not significantly changethe soil organic mattercontent，and NPKMS significantly increased soil organic matter content by20.6%.Compared withNPK，NPKM and NPKMS did not significantly change soil totalnitrogen，available phosphorus andpH.Compared withCK，NPK did not significantly change soil enzymeactivity，and NPKM and NPKMS significantly increased soil enzymeactivity. The analysis of structural equation modelling showed that soil available phosphorus and invertase activitiy were the majordriving factors.Returning straw to the field and replacing 30% of chemical fertilizer with organic fertilizer can increase maizeyield and soil organicmatter，and is an important measure to achieve fertilizer reduction and soil fertility improvement.