In view of the characteristics of semi-structured customer needs ( SCNs) with fuzziness and difficulty to be processed and converted to precise product functional requirements ( FRs) ，an expressing and transforming approach for SCNs is studied． The mathematical description approach of SCNs and the formal description approach of SCN transforming problem are presented，and then the architecture of the SCN transformation is constructed． This architecture is composed of four steps: fuzzy semantic analyzing，intelligent fuzzy reasoning，weighted optimizing，and defuzzification． Precise product functional requirements satisfying SCNs are outputted at last． Finally，the practicability of the approach is illustrated by an application case．