Foam fractionation for recovering leaf protein from alfalfa (Medicago sativa L.) has been investigated. The extraction yield of alfalfa leaf protein (ALP) from the dried alfalfa leaves reached 71.90% under the extraction conditions of pH 8.0, temperature 70 degrees C, and extracting time 40 min. For strengthening foam drainage at room temperature, a novel foam fractionation column with a cross-internal component covered superhydrophobic coating was developed. By using the extraction liquor as the feeding solution, a two-stage foam fractionation had been performed. Under the suitable operation conditions, the enrichment ratio and the recovery percentage of ALP were 4.33 and 89.0%, respectively.