Abstract: This paper intends to put forward a semi-quantitative method of prediction of solar proton events, i.e., to estimate the peak intensity of solar protons and the rise time in which solar protons expense to reaching it’s peak intensity from the onset of the optical flare presumed to have been identified as a proton flare.We had collected and studied statistically the systematic data of solar proton events and associated solar flare and radio burst data published abroad.The statistical results show that the correlation coefficient between the rise time t of solar proton event and the flare heliographic longitude 0 is about 0.87 and the fitting equation is t=18.1-0.39θ+0.0033θ2.Furthmore, the solar radio data of six frequencies(9400, 8800, 4995, 2800, 1415, and 606 MHz)were analysed and fitted to the equation lgP=AlgK+B.Among them, the correlation between the 8800MHz radio parameters and the solar proton intensity is the best.The correlation coefficients between the averge flux, the peak flux and the integrating flux of the 8800-MHz radio-burst events and the peak intensity of solar proton events are 0.70, 0.68 and 0.69 respectively.The coefficients can be raised to 0.77, 0.77 and 0.75 respectively if two large proton events occured in August, 1972 are also considered.Thus, using the corresponding empirical equation, We cam forecast the rise time and the peak intensity of solar proton events from the observed data of the solar flare longitude and the fluxes of the 8800MHz radio burst.