Abstract: 【Objective】 To study thotosynthetic characteristics and wine characteristics of wine grape Marselan in extremely arid region in the hope of providing theoretical basis for promotion and vinification. 【Method】 A newly introduced wine grape Marselan and local main variety Cabernet Sauvignon were used as materials,the Li-6400 photosynthetic apparatus was used to measure light response curve and FMS-2 por Table pulse-modulated fluorometer was used to measure chlorophyll fluorescence parameter,basic physical & chemical index and phenolic index were measured and single breed brewing test were conducted when the fruit was ripe,and wine quality was measured too,then photosynthetic characteristics and wine characteristics of wine grape Marselan were comprehensive assessed in extremely arid region. 【Result】 The maximum net photosynthetic rate of Marselan leaves was higher than that of Cabernet Sauvignon,however light combination point and dark respiration rate were lower than those of Cabernet Sauvignon,which showed that Marselan had strong tolerance to low light.F_m,F_v/F_o,F_v/F_m,ΦPSII and NPQ of Marselan leaves were higher than those of Cabernet Sauvignon,while Fo of Marselan’ leaves was much lower than that of Cabernet Sauvignon.There was no significant difference between ETR of Marselan and Cabernet Sauvignon.Marselan had greater light utilization potential,and PSII could maintain high photochemical activity and protect the reaction center from damage.Soluble solids and reducing sugar content rise of Marselan were faster than Cabernet Sauvignon in later fruit ripening,however total acid of Marselan was slower than Cabernet Sauvignon,Marselan could keep a high total acid content,total phenols and tannins content of grape peel showed a trend of slow increase and then a slight decrease, while total anthocyanins showed a trend of first increase and then a slow decrease.Marselan could accumulates more phenols.Cluster mass and berry mass of Marselan were heavier than Cabernet Sauvignon,Marselan had medium bunch density,dark color of skin and seed,better maturity,peel quality,soluble solids,reducing sugar,total acid,anthocyanins and tannins,compared with Cabernet Sauvignon,Marselan had higher basic wine quality,alcohol content,total acid,chromaticity,total phenols and anthocyanins were higher than those of Cabernet Sauvignon,while pH was lower.In terms of fruit quality,Marselan was superior to Cabernet Sauvignon. 【Conclusion】 Compared with Cabernet Sauvignon,Marselan has greater light utilization potential,PSII can maintain high photochemical activity,proper picking stage at the end of August and it has wine characteristics in extremely arid region.