Spirulina platensis was grown in swine waste to reduce inorganic compounds and simultaneously produce feed resources. Spirulina platensis prefers nitrogenous compounds in the order: NH 4 + -N>NO 3 - -N>simple-N such as urea and simple amino acids. It even consumes NH 4 + -N first when urea or nitrate are present. Therefore, the content of residual NH 4 + -N in Spirulina platensis cultures can be determined by the relative extent of the following processes: (i) algal uptake and assimilation; (ii) ammonia stripping; and (iii) decomposition of urea to NH 4 + -N by urease-positive bacteria. The removal rates of total nitrogen and total phosphorus were estimated as an indicator of the treatment efficiency. It was found that Spirulina platensis was able to reduce 70-93% of PO 4 3- -P, 67- 93% of inorganic nitrogen, 80- 90% of COD, and 37-56% of organic nitrogen in various concentrations of swine waste over 12 days of batch cultivation. The removal of inorganic compounds from swine waste was mainly used for cell growth, however, the organic nitrogen removal was not related to cell growth. A maximum cell density of 1.52 dry-g/l was maintained with a dilution rate of 0.21/day in continuous cultivation by adding 30% swine waste. The nitrogen and phosphorus removal rates were correlated to the dilution rates. Based on the amino acid profile, the quality of the proteins in the Spirulina platensis grown in the waste was the same as that in a clean culture.