The former of e-business today is electronic commerce. E-commerce itself is just transaction via the Internet. Every company cannot do business without products. They may be physical goods or services. The company that sells perishable products (vegetables) has been mentioned and inventory problem is the heart of this study. The study uses the fixed -order interval inventory policy for finding optimal value. Based on the theoretical model, some particular cases are given to illustrate the algorithm. Further, the study also deals with promotion program, which is essential for business today.