Based on the integrated analysis of the cloud data obtained by digital radar， and the particle measuring system made by DMT company, the main cloud physical parameters used to identify cloud seedability are proposed. The vertical distribution of cloud supercooled water content from 0℃ layer height (1500 m) is calculated as follows: the cloud water content has a maximum of 0.416 g·m-3 at 400 m height above the 0℃ layer, then as the distance from the 0℃ layer height increases, the supercooled water content in clouds decreases, rapidly reaches to the lowest at the 600 m height above the 0℃ layer, from this height to the cloud top, the cloud maintains low water content. Only when the relevant cloud particle concentration obtained by CDP probe of DMT is larger than 30 cm-3， would the cloud area have certain seedability. Furthermore， when the particle concentration obtained by CIP probe of DMT is less than 10 cm-3， the cloud would be highly seedable and otherwise it is generally seedable.