To provide a network system for an embroidery sewing machine which can flexibly cope with both of a multiple kind-small amount production and a mass-production.

An administration software which is installed in a personal computer for a quantitative change such as a production number is connected with sewing machines through this network, and an optimal sewing condition for the sewing machines is calculated, and an embroidery can be performed. When the production amount is large, all sewing machines are operated by synchronizing the frames and the rotation numbers such as a multiple head embroidery sewing machine. Then, when the production amount is a multiple kind-small amount, the sewing machines can be operated as single head embroidery sewing machines as well.