[Objective] To study variation characteristics of vegetation net primary productivity in north of Shaanxi Province based on MOD17A3.[Method]Based on the annual NPP data and GIS technology from 2000 to 2010, the temporal and spatial variation characteristics of vegetation NPP in Northern Shaanxi were quantitatively analyzed based on MOD17A3.[Result]The results showed that the average NPP of the North and South of Yulin was 151-250 g C/(m2· a).The average NPP was more than 300 g C/(m2· a) in the southern part of Yan'an. From Yan'an and Yulin, the increase of NPP in the two cities were 92.9％, 97.8％ respectively.Compared with NPP in 2010, the majority of the region has increased, and only a few areas have been reduced.Rises in 0-50 g C/(m2· a) areas along the Great Wall area of Yulin, increase in 51-90 g C/(m2· a) in northwest region has the most of Yulin and Yan'an, rises in 91-120 g C/(m2· a) and the presence of >120 g C/(m2· a) above the main central southeast of Yulin and Yan'an;The decrease of NPP was mainly distributed in the Bridge Mountain Region and Huanglong Region in the south of Yan'an.[Conclusion]The study suggested that through the implementa-tion of a series of ecolog-ical construction projects such as closing hill for forestation and restoring farmland into forestland,the vegetation in these parts was improved.