An understanding of the actual and potential size of the industry is important not only to evaluate investment decisions, but also to determine the market share of each of your competitors.
You can make an estimation of the actual size of the industry by referring to several second hand research sources like the China National Bureau of Statistics or Department of Commerce and Trade, as well as industry associations. These sources often provide market information, charts of sales by product line, growth, geographic markets or major players in the industry.
To project the potential size of the industry, you will have to look closely at gaps within the industry. Such gaps may be in product lines, distribution, usage, competitiveness or any number of other areas. By gathering research on your customers, competitors and the industry, you will be able to spot those gaps.