Abstract: The investment in nine partical board Plants in Guangdong Province and their production were studied. Six indices, i.e. rate of proit and tax on investment, rate of profit on investment, rate of output value on fixed assets, rate of profit and tax on output value, labor productivity, and payback perlod, were applied to evaluate the economic benefit of p artical board projects in Guangdong Province. The input-output mathematical relation of nine partical board plants in Guangdong Province was regressed. After evaluation and regression, the results showed that the economic benefit of the partical board projects was not goods partical board industry belonged to erpital -intensive; the operation scale of partical board industry should not he too large; the relation between capital and output value could be positively correlrted; the relation between la' or and output value showed negative Correlation.