The aim of this study was to evaluate the effect of replacement of different levels of diet quality forages with date palm leaves on the performance of Holstein dairy cow in end lactation. In this experiment, 9 multiparous Holstein dairy cows by 206.5 ± 8.23 days in milk, milk production = 41.09 ± 4.88 kg; body weight = 692 ± 50 kg and body condition score =3.03 ± 0.4 (mean ± standard deviation) were used. As well, this experiment was designed conducted in a 3*3 repeated Latin square in 3 square, 3 treatment and 3 period by every 28 days. Experimental treatment were: 1) Diet containing 0% replaces corn silage forage and alfalfa with date palm leaves, 2) Diet containing 50% replaces corn silage forage and alfalfa with date palm leaves, 3) Diet containing 100% replaces corn silage forage and alfalfa with date palm leaves. The diets were balanced according to energy, protein and neutral detergent fiber which had a geometric mean of 4.79, 4.1 and 3.44 mm respectively. In experimental diets, with increasing level of date palm leaves, retained dry matter on 19, 8, 1/18 sieve and bottom pan were not affected by the treatments (P 0.05). Physical effective rate in 2 sieves and 3 sieves were not affected by experimental treatments (P 0.05). Physical effective fiber percentage at experimental rations in 2 and 3 sieves system were not affected by treatments (P 0.05). Dry matter intake in 19 and 8 mm sieve was affected by treatments (P 0.05). Selection index at 19 and 8 mm sieve was affected by treatments and increased with increasing level of date palm leaves. Dry matter intake were affected by treatments and decreased with increasing level of date palm leaves (P 0.05). The digestibility of dry matter and organic matter were affected by treatments (P 0.05) and decreased with increasing level of date palm leaves. ECM, FCM and milk fat percentage were not affected by treatments but numerical decreased with the increase level of date palm leaves (P 0.05). Total eating times and eating rates were not affected by the increase in the level of date palm leaves (P 0.05). There was no significant difference in rumen pH and ammonia nitrogen (P 0.05). Blood urea nitrogen, glucose, albumin and total protein were not affected by treatments (P 0.05). In general, the results of this experiment showed that the consumption of concentrate with 50% of date palm leaves could be used to feed Holstein dairy cow in end lactation without negatively affecting the performance of dairy cow. Keywords: Palm leaf, uNDF, dairy cow performance, peNDF