The spatial distributions of jujube roots under two methods of drip irrigation and furrow irrigation in two years were researched by soil core and scanning methods in arid area. The results showed that the length of total roots and absorbing root、the number of root tips and forks、the root surface area and volume of root under the drip irrigation were 15.4%,13.9%,24.8%,39.7%,29.9% and 47% respectively which were larger than that under furrow irrigation. It explained that the drip irrigation could add roots. Thus the drip irrigation increased the ability of absorbing water and nutrient of jujube roots. And the 2D model of the spatial density distributions of effective root in length was established by the exponent function. It offered evidences for the improvement of drip irrigation technology in arid area.