Caustic soda with the formula of NaOH, is an inorganic compound and a highly caustic base and alkali. It is a co-product of chlorine production and can be used in a variety of manufacturing processes. 

Caustic soda is used to manufacture many everyday products including:
1. extracting alumina from naturally occurring minerals. 
2. being used in chemical industry, manufacturing rayon, spandex, epoxy resins, paints, glass, ceramics and making dyes.
3. making paper
4. producing sodium hypochlorite, a water disinfectant.

China's caustic soda downstream demand mainly came from alumina, chemical industry and papermaking, which accounted for a large proportion with the share of 34%, 16% and 14% respectively.

From 2013 to 2017, China's caustic soda output showed a rising path in general despite of a slight drop to 30.3 million tons in 2015. The output was 33.652 million tons in 2017, increasing by 2.5% from a year earlier.

During these years, caustic soda consumption quantity has also shown a similar trend. It reached 32.143 million tons in 2017, increasing by 3.9% from 2016.

From the perspective of China's caustic soda region distribution, Shandong Province accounted for a large proportion with the share of 28.59%.