This book is focused on inventory models with Stock-Dependent Demand (SDD) with special reference to items that deteriorate over time. The author has developed mathematical models with Quality Dependent Demand (QDD) where the demand rate is influenced by both the quality and quantity. Two types of SDD are considered, one with Inventory Level Dependent Demand (ILD), and the other with Lot Size Dependent Demand (LSD). The innovative feature added to the existing literature is the effect of temporary Stock-Dependent Demand.