In order to evaluate the active ingredient, grain yield of common buckwheat (fagopyrum esculentum) affected by sowing date, planting pattern and nitrogen in summer cultivation, a field study was conducted during 2018 and 2019 in Agricultural Research Institute of Arak, Iran. The experimental design was regarded as the randomized complete blocks in the form of split-plot factorial with three replications. Planting pattern treatments as the primary factors included two levels of 50 cm mound with two 20cm sowing rows (P1) and 60cm mound with three 15cm sowing rows (P2). Sowing date treatments included four levels of 20th June (D1), 5th July (D2), 20th July (D3) and 5th August (D4) and nitrogen treatments included four levels of 0 (N1), 50 (N2), 100 (N3) and 150 (N4) kg ha-1 considered as secondary factors. Results showed that the effects of planting dates, nitrogen and planting patterns have been significant on grain yield, rutin percent rates of leaves, stem, grain and flower. So, the highest rates of grain yield as 1967 kg ha-1, leaf, stem, grain and flower rutin percent as 0.99, 0.37, 0.007 and 1.35 mg per 100 g of dry matter have been observed for the treatments of P2D1N3, P2D4N4, P1D4N4, P1D4N3 and P1D4N3; respectively. Therefore, buckwheat with nutritional characteristics, adaptation, good yield as a new medicinal plant can enter the cultivation patterns in different regions of the world.