Abstract: In order to investigate the effect of the quantity of primer combinations on genetic diversity parameters in Rhododendron delavayi, the amplified fragment length polymorphism (AFLP) was employed to test 4 natural populations of Rhododendron delavayi with 5, 7, 9, 11 and 13 AFLP primer combinations. The results showed that the genetic diversity parameters of Zixi Mountain population had same changing trends with the increase of primer combinations quantity, which indicated that the amplified resutls with 5 primer combinations were slightly higher than that with other primer combinations, but the differences were not significant. The changing trends of genetic diversity parameters in other 3 populations were not obvious. There was no significant effect on the genetic distance between populations and the cluster results were consistent based on unweighted pair group method analysis (UPGMA) with different numbers of primer combinations. So, it could be concluded that 5 primer combinations could provide accurate results of Rdelavayi genetic diversity.