Abstract: The technological optimization of alkali pretreatment in the course of carrageenan extraction from Eucheuma gelatinae was studied by the response surface methodology. On the basis of single-factor investigation, the quadratic regression equations about yield and gel strength ( GS) of carrageenan were established regarding KOH mass fraction, alkali-pretreating temperature and alkali-pretreating time as influence factors, and yield and strength of carrageenan as response values, the optimal conditions for the alkali pretreatment were analyzed by the response surface methodology.The optimizing process parameters were as follows:KOH mass fraction 10%, alkali pretreating temperature 56 ℃ and alkali pretreating time 6 h, under the conditions, yield and GS of carrageenan from Eucheuma gelatinum were 75.23% ± 2.16% and ( 1378.5 ± 16.27) g/cm2 respectively.The optimized process could effectively improve the producting conditions for the carrageenan extraction from Eucheuma gelatinae.