A novel periodic long-range surface plasmon resonance( LRSPR) sensing structure is proposed for high sensitivity sensor design. Periodic LRSPR structure complete simulation on two cost functions which are sensitivity and full width at half maximum( FWHM) by genetic algorithm. The simulation results show that the sensitivity and FWHM of this structure reach the optimum under the 40-layer structure. Compared with the traditional surface plasmon resonance( SPR) structure
the designed structure has higher sensitivity and very narrow FWHM
which provides a structural idea for the design of high sensitivity sensor.