The effects of 3 water saving irrigation models namely shallow-wet-dry irrigation, intermittent irrigation and aerobic irrigation on population growth characteristics of rice were studied. The results indicated that the tillering process was delayed, tiller number was increased by 27～54 tillers/m2 compared with conventional irrigation. The spike rate were increased by 3.2%, 13.9%, 12.8% respectively. Root dry weight and root shoot ratio were higher than conventional irrigation.