By using the data from the groundbased dualfrequency microwave radio meter of 23.8 and 31.65 GHz, satellite cloud picture, the data from weather rada r, radiosounding and selfrecording rain gauge, analyzed was the evolution of a t mospheric integrated precipitable water (V) and cloud liquid water content ( L) o btained in different cloud conditions in April of 2005 in Xingxiang, Henan. Spe cial analysis was focused on the effect of low trough cloud system on April 8. T he results showed that the radiometer is sensible to the water vapor and liquid water in clouds, and different V and L correspond to different weather b ackgroun d. The variation in L is related to the increasing or decreasing of cloud wa ter content. There is an obvious fluctuation in L before rain and increase sig nifica ntly during rain. Generally when L reaches 0.4 mm, the precipitation happen s. This reveals that cloud is developing and will rain. In addition, the relations hip among the three kinds of atmospheric water, i.e., precipitable water, cloud water and precipitating water, was analyzed based on the observation data. The results showed the ratio of L and V is 0.0087, whereas the rainfall amou nt is only 18% of precipitable water.