Afro-Asian subtropical westerly jet stream in the Eastern Hemisphere is formed from West Africa through the Arabian Peninsula,South Asia and East Asia to the North Pacific.Currently,most studies on the Afro-Asian subtropical westerly jet streams have focused on the East Asian westerly jet stream,which lies in the eastern part of Eurasia,but less attention has been paid to the Middle East westerly jet stream(MEJ),which situates in the western part of Eurasia.The MEJ is an important circulation system that affects the climate of Northern Hemisphere’s mid-latitude regions and is closely related to the climate of China.Here,by means of National Centers for Environmental Prediction/National Center for Atmospheric Research monthly reanalysis data,and sunspot data provided by National Oceanic and Atmospheric Administration,the inter-annual variation characteristics of wintertime MEJ and solar cycle modulation of the relationship between North Atlantic Oscillation(NAO) and MEJ axis south-north shift are studied.The results show that wintertime MEJ axis north-south shift has obvious inter-annual variation feature.The spatial variation of MEJ manifests axis shift east-west out-phase(MEJAO) pattern and axis shift in-phase(MEJAI) pattern.Furthermore,solar activity has obvious 11-year period.In the high solar activity cases,the location of NAO’s spatial structure is more close to the continent that is situated near the east of North Atlantic,and there are opposite sea level pressure(SLP) anomalies at the north of Europe and Mediterranean Sea.Through Ekman pumping,these anomalous SLP can bring secondary circulation and Mediterranean convergence(MC) anomaly at the high level of troposphere.By Rossby wave train excited by anomalous MC,there are geopotential height anomalies in Iran Plateau at the high level of troposphere,which can lead to westerly opposite changes between south and north sides of eastern MEJ axis.In addition,there are geopotential height anomalies in southern Europe at the high level of troposphere,which can bring to westerly anomalies at north side of western MEJ axis.The distribution of westerly anomalies between south and north sides of the eastern MEJ axis is opposite to that of western MEJ axis,which is manifested MEJAO pattern.In the low solar activity cases,the spatial structure of NAO is located at the Atlantic,which is difficult to form MC anomaly.The relationship between NAO and MEJAO pattern is not obvious.Therefore,there is solar cycle modulation of the relationship between NAO and MEJ axis shift.