The field experiment was carried out during the two successive winter seasons 2017/2018 and 2018/2019 in private sector farm at Badr center, El-Behira Governorate, to investigate the effect of mineral and bio potassium fertilizer as well as the foliar spray with different sources of boron (chelated boron, boric acid and nano boron) on growth, chemical composition, fruit yield and quality of strawberry plants (Fragaria X ananassa Duch) cv. Sensation. This experiment included 16 treatments resulted from the combination between four potassium fertilizers treatments,  100% recommend dose of mineral potassium fertilizers 350kg potassium sulphate (The control treatment), 120% recommend dose of mineral potassium fertilizers 420 kg potassium sulphate,  80% recommend dose of mineral potassium fertilizers 280 kg potassium sulphate+ potassin and   60% recommend dose of mineral potassium fertilizers 210 kg potassium sulphate+ potassin  as well as four foliar spray treatments,  chelated boron at 100ppm,  boric acid at 100ppm, nano boron at 100ppm and the control treatment (spray with tap water). Obtained results showed that application of 80% recommend dose of mineral potassium fertilizers + potassin bio fertilizer (280 kg/Fed. potassium sulphate+ potassin) then spray the plants six times starting after 30 days of transplanting and every 15 days intervals with Chelated boron at100ppm exhibited the highest values in all measured growth parameters, chemical composition of plant foliage,  exportable yield as well as total produced yield with best fruit quality.