To easily and immediately realize the simulation of home breeding or home cultivation in a further realistic and satisfying form by enabling a person to obtain a real result such as livestock product or agricultural product by performing a computer simulation of livestock breeding or crop cultivation.

A breeder or cultivator performs the simulation of livestock breeding or crop cultivation on a computer terminal connected to a network. The data of the simulation are transmitted to a seller of livestock product or agricultural product through the network. The seller sends a livestock product or agricultural product having the quality and volume corresponding to the growing degree of livestock or crop at the end of the simulation to the breeder or cultivator.