Three-Dimensional model of static random access memory （SRAM） six-transistor cell is generated by three dimensional process simulator FLOOPS, and device simulator DESSIS is used to simulate the single-event upset effect in SRAM. Single-event upset and charge collecting maps are calculated directly from 3-D simulations. Single event upset maps and cross-section curves obtained from numerial simulation show excellent agreement with broad beam cross section curves and micro-beam upset images for 2 kbit hardened SRAM. It indicates that the three-dimensional model could be used to research the single event upsets in SRAM.