Hydroxypropyl Methyl Cellulose (Hydroxypropyl Methyl Cellulose, abbreviated HPMC), also known as hypromellose (Hypromellose), with CAS No. 9004-65-3, is a non-ionic cellulose ether blend. It is a semi-synthetic polymer compound made from natural cellulose (refined cotton or wood pulp) as raw material through alkalization and etherification reactions. It has the characteristics of being odorless, tasteless, non-toxic, and its appearance is white to off-white powder or loose fibrous solid.

As one of the most widely used cellulose ether varieties, HPMC is widely used in many fields such as building materials, medicine, food, daily chemicals, and petroleum chemicals due to its excellent thickening, water retention, film-forming, binding, and flow-regulating properties, and is known as the "industrial MSG".