Analysis of the jet stream is diagnostic over Baghdad for period studies 2012 to 2014 using Radiosonde data and synoptic charts. The source of data is Iraq Meteorological Organization and Seismology (IMOS). Similar way for weather forecasts to identify areas, forecasters show that area has good predictability under jet stream case. The jet stream is happening clearly realized under the climatic conditions like temperature, humidity and geopotential height for upper layer. Two levels 300hPa and 500hPa is the best way to determine the current jet. Maximum frequency of jet stream happened in April and July in 500hPa that equal 13 times and in 300hPa happened 14 times in May. This study showed that the occurrence of cases of the jet stream is becoming increasingly volatile and decreasingly during 2012 and gradually increased in 2014 where that recorded in 2014.