In this study, sodium borohydride (NaBH4) is synthesized from Na and MgH2 in the presence of B2O3 that behaves as a stickiness inhibitor and boron source. All experiments are performed under argon atmosphere via ball milling, without applying high temperature or pressure. An optimum synthesized parameter is searched with reaction time and stochiometric ratio. Mechano-chemical reactor working time is varied from 100 to 1,100 min, while stoichiometry of B2O3/Na ranges over 0.6-1.4, and MgH2 is used 30% in excess. FT-IR and XRD instruments are utilized to analyze the products. Additionally, hydrogen contents of the untreated products are measured with the inverse burette technique. Consequently, results show that long reaction times favor the yield. Moreover, equalizing the amounts of B2O3 and MgH2 can raise NaBH4 yield to 25% or more.