Effects of different irrigation time of groundwater on growth and yield of rice were analyzed in the paper. The results indicated that effects were obvious. Compared with irrigation at 5:00 PM, the initial tiller stage of rice irrigated at 8:00 AM was delayed by five days, the effective tiller stage was delayed by six days, the maximum tiller number stage was delayed by six days, the heading stage was delayed by four days, the maturation was delayed by four days, and the yield was decreased by 5.3%.