By using a bubble column a globular protein soluble in water was continuously floated at a pH value of 5.3 near is isoeletric point in order to remove and concentrate it tvom its aqueous solution under the co-existence of a supporting electrolyte. The obtained experimental data were summarized in terms of the dynamic surface excess (surface density), and the relationship between the excess and the bulk concentration could be formulated by a Langmuir type equation. By varying the feed concentration and the column height the transient behaviours of the excesses were also examined, and the result could be formulated by the adsorption rate equations proposed by the present authors.