Measurements of stratus cloud microphysical properties were carried out in Hebei Province in October 1990 and April 1991 using a aircraft PMS（Particle Measurement System）.The analysis results will be useful for studies on global climate change,satellite remote sensing and aircraft measurement.In this paper,the cloud micro-properties and vertical structure are preliminarily analyzed,and the relationship between aerosol and cloud droplets is also analyzed.The results show that,in the early 1990s,the cloud-droplet number concentration is 79.2cm^-3 and the liquid water content is about 0.03g·m^-3.The effective diameter for stratus cloud drops is around 11m and it varies vertically.There is a positive correlation between aerosol number concentrations below the cloud base and cloud droplets number concentrations.