A stratiform cloud wasmeasured with a ParticleMeasurement System ( PMS) p roduced byDrop letMeasurement Technologies (DMT) and mounted on a Y - 12 aircraft in sp ring of 2008, Beijing. It was found that the average concentration of cloud particles measured by CAS (Cloud and Aerosol Spectrometer) was bigger than those valuesmeasured by FSSP in other areas of north China. It was also found that the average concentrations of ice particlesmeasured by CIP (Cloud Imaging Probe) , 2D - C and 2D - GA2 were all similar. A positive correlation was found between snow and ice crystals’concentrations. A negative correlation was found between the concentration of ice crystal and the ratio of snow and ice crystal concentrationswhen the concentration of ice crystalswas less than 104 m- 3 , butwhen more than 104 m- 3 , the ratio of snow and ice crystal concentration is a constant. Many ice crystals were found in the cloud field where the temperature ranged from - 10 to - 12 ℃, and there wasmore supercooled water in the field. The p recip itation particleswere p ropagated in the cloud filed where the temperature ranged from - 7 to - 10 ℃. Precip itation particles evaporated and became smaller in the cloud filed where the temperature ranged from - 5 to - 7 ℃. L ittle p recip itation particleswas found in the cloud field where the temperature ranged from - 4 to - 5 ℃.
