The effects of El Ni(n)o Modoki events on global ozone concentrations are investigated from 1980 to 2010.El Ni(n)o Modoki events cause a stronger Brewer-Dobson (BD) circulation which can transports more ozone-poor air from troposphere to stratosphere, leading to a decrease of ozone in the lower-middle stratosphere from 90°S to 90°N.These changes in ozone concentrations reduce stratospheric column ozone.The reduction in stratospheric column ozone during El Ni(n)o Modoki events is more pronounced over the tropical eastern Pacific than over other tropical areas because transport of ozone-poor air from middle-high latitudes in both hemispheres to low latitudes is the strongest between 60°W and 120°W.Since the decrease in stratospheric column ozone during El Ni(n)o Modoki events, more UV radiation reaches the tropical troposphere leading to significant increases in tropospheric column ozone.An empirical orthogonal function (EOF) analysis of the time series from 1980 to 2010 of stratospherie and tropospheric ozone monthly anomalies reveals that: El Ni(n)o Modoki events are associated with the primary EOF modes of both time series.We also found that El Ni(n)o Modoki events can more significantly affect the global ozone than canonical El Ni(n)o events.These results imply that El Ni(n)o Modoki is a key contributor to variations in global ozone from 1980 to 2010.