Abstract:A nonvacunm pulse electron beam generator of pocket size has been developed.Usingthis instrument ,the mutagenic effects of nonvacum electron beam on pea seeds of varietyJLBP(Jilin big pea)were studied.The results showed that the NPEB(nonvacuum pulse elec-tron beam)is a very effective mutagenic source, which could induce higher chromosomeaberrations and strongly inhibit the development of M1 generation,Mutants with variousqualitative and quantitative characters as well as higher chlorophyll defect frequency andchlorosis were obtained in M2 generation,The optimum dose of the uonvacuum pulse electronbeam is 3.3 × 102Gy～4.4 × 102Gy.The instrument is safe and easy to operate。