Abstract: Capillary water has a significant influence on moisture migration and salt dynamics. The relationship between the rising height of capillary water and time was obtained from the comprehensive tests on the rising height of capillary water in sandy soil with five kinds of different fly ash contents using the method of standpipe. The results show that capillary water rise process can be divided into three stages including fast rise,slow rise and plateau stage. The corre- sponding times of the first two stages increase with the increase of fly ash content,and the relationship between rise time and fly ash content can be fitted as quadratic polynomial. The relationship between rising height of capillary water and time can be better fitted by the power function,and thus the calculation equations are obtained. The largest rising height of capillary water linearly increases with the increase of fly ash content.