The aim of this study was to evaluate the physiological and morphological characteristics of Narcissus tazatta in response to benzyl adenine (BA) and nano-potassium fertilizer. This experiment was done as factorial with two factors of benzyl adenine hormone and nano-potassium fertilizer in a completely randomized design with ten replications.  Benzyl adenine in four levels (0, 500, 750 and1000 ppm) and nano-potassium in three levels (0, 1.5 and 2.5 gr/l) were applied as spraying the solution on plants. Results showed significant effect of benzyl adenine hormone on water absorption rate and the number of flowers in 1% probability level (P<0.05). Besides, the effect of different levels of fertilizer on water absorption rate, diameter of the stem, length of stem, wet and dry weight of the flower and the number of flowers was significant. The maximum diameter of the stem was obtained with 1.5 gr/l nano-potassium fertilizers. In the interaction between hormone and fertilizer, maximum concentration of antocyanin was seen by 750 ppm BA and 2.5 gr/l nano-potassium with an average e of 0.6 µg in a gram of wet weight of the plant. The highest water absorption rate was obtained through the application of 2.5 gr/lit nano-potassium and 500 ppm BA. Therefore, the results of this experiment indicate that hormone and fertilizer of nano-potash cause to increase quality of flower. Manuscript profile