This study is a basic research for the estimation of the value of unpaid household labor within the national economy system to be reflected in the related policy-making. By measuring economic value of unpaid household labor and estimating the ration to GDP, this study attempted to confirm the productivity of the unpaid household labor and thus contribute to the improvement of socio-economic status of women. Especially, it focused on the development of a standard of estimating unpaid household labor as a method applicable to the present economic and legal system. To organize the method of economic valuation of unpaid household labor and calculate the ration to GDP, this study used three approaches: replacement cost method individual function, replacement cost method generalist and opportunity cost method. Although the estimated result revealed that the economic value of unpaid household labor showed a great extent of deviation according to the estimating methods and the wage rate, total value of household labor ranged from one hundred and thirty eight to two hundred and thirty trillion wens, about 28-48% of GDP in Korea.