<正> A method of nylon solid phase radioimmunoassay（SPR）was developed andused in the determination of α-fetal protein（AFP）.Nylon grains were activated and con-jugated with IgG to form a solid phase IgG.The activity of solid phase IgG was stableand it can be maintained for near 3 years at 4℃.At room temperature the activity didnot obviously change in 13.7 months.The method is simpler and more convenient thanliquid phase radioimmunoassay（LPR）.The reactive error relation（RER）of this methodwas 0.01 and the precision curve was perfect.Sixty seven samples were measured withboth the solid phase method and double antibody-PEG（polyethylene glycol）.Results ofthe two methods were not significant in difference（P>0.05）.The correlation coefficientof the two methods was 0.97（P<0.01）.It was proved that nylon was a very good solidphase carrier for SPR.