The computer simulation of detecting fruit by visual feedback on hand-eye system was done in order to investigate detecting accuracy under the various conditions. From the result, it was obtained as follows : 1. The smaller the distance from the visual sensor to the fruit was smaller, the error by visual feedback became smaller proportionally. 2. The error depended on the fruit diameter. 3. The bigger the picture element number was, the smaller the scattering. 4. The bigger the manipulator speed was, the bigger the picture element number recognizing fruit became, and the error became bigger. 5. It was not suitable that visual feedback on hand-eye system was independently used for detecting fruit whose diameter had the scattering fairly.