Based on our previous studies, we successfully cultivatied protein-rich forage rice in a real-scale field with the area of 30 ale by continuous irrigation using treated municipal wastewater (TWW). The yield (6.58±0.50 t/ha) and protein content (9.76±1.09 %) were significantly higher than those of the same variety of rice harvested in the normal field under the standard practice. An experiment on feeding pigs at the latter growth stage by the protein-rich rice was conducted in this study. Comparing with the general (control) feed composed of corn and soybean cake as sources of energy and protein, respectively, the feed using the protein-rich rice as proxy of corn was tested in the feeding experiment. When the test feed was designed, the usage of soy-bean cake, which is more expensive than corn, could be reduced due to a higher content of proteins in the rice than corn. In the feeding experiment, the pigs fed by the test feed demonstrated a significantly higher yield of dressed carcass than those done by the control feed. The test feed achieved a higher carcass grading than the control feed, although its difference was not significant, and a comparable meat quality indicated by nutritional and physical parameters. To examine its feasibility, the economic evaluation was applied to the project in Tsuruoka municipal wastewater treatment plant to supply TWW to 19 hectale paddy fields cultivating protein-rich rice and to use the rice harvested there for pig farming. It revealed that the investment of 3.5 million JPY/year for TWW supply to the paddy fields can produce the benefit of 5.3 million JPY/year (including bonus for paddy farming) for rice and pig farmers, although the farmland, which are now shared by many rice farmers, has to be consolidated to improve the productivity.