Abstract: The relationship between potato yield,other traits and plant density were studied in high altitude arid area by plant density test. The results showed that potato yield increased with the increase of plant number in a proper range, but it decreased with the increase of density when the density reached a certain level. The plant yield and numbers showed a conic model change as Y=12 487.475+5 160.417 2X-236.968 6X², where X and Y ware plant numbers and yield, respectively. A positive correlation was found between plant height and density, the equation was Y=96.566-85.513/X. The optimal density was 75 000 plant per hectare for the best yield in high altitude arid area. The density was negatively correlated with weight per plant and commodity rate, while the function models were conic curves that decreased with the increase of density. There was a positive correlation between commodity rate and the weight per plant,while there was a negative correlation between the plant height and weight per plant and commodity rate. Plant height increased,the rate of commercial tuber and the weight of tuber per plant decreased.

Key words: potato, density, function model