Abstract: The Arctic probability distribution of cloud phase, cirrus clouds top temperature, cirrus clouds top height, cirrus clouds optical thickness and effective radius in summer were presented based on Moderate resolution Imaging Spectrometer(MODIS) cloud product data(MOD06) of 2011-2014 in July, and the relationship between effective radius and cirrus clouds top height was discussed. Results show that in summer the occurrence frequencies of cirrus clouds become higher while the occurrence frequencies of water clouds become lower in the Arctic. Cirrus clouds top temperatures mainly distribute in the 230-272 K(that is -43℃ to -5℃). The cirrus clouds top height distribute from 2 to 8 km, and has a highest occurrence frequency in the range of 4.5-6 km. The cirrus clouds optical thickness is less than 10. The cirrus clouds effective radius distribute from 5-40 m and most probable appear in the range of 10-20 m. The relationship of cirrus clouds effective radius and cirrus clouds top height has a positive correlation in the Arctic, while in mid-latitude this relationship is opposite. The higher the cirrus clouds top height,the greater the cirrus clouds effective radius is. In the Arctic, with the increase of the latitude, the cirrus clouds occurrence frequency, cirrus clouds top height, cirrus clouds effective radius and cirrus clouds optical thickness increase, while the cirrus clouds temperature decreases.