Bubble loading is the mass of hydrophobic particles attached per unit surface area of air. This measure can be used in the design and analysis of flotation columns as a sign of true flotation. To date, however, this measurement has been limited to the pulp-froth interface, which only indicates the maximum bubble loading and does not reflect the progress of the loading process. This paper introduces the concept of bubble loading profile that summarizes measures of bubble loading at different heights of the collection zone in a flotation column. The effects of bubble size, particle size and collector dosage on the introduced profiles are also investigated. These operational variables changed the bubble loading profile from a linear to a curved trend. The curvatures in the profiles were near the place of the feeding port and therefore the collection zone was divided into two separate zones in terms of bubble loading characteristics. The zone below the feeding port often did not contribute much to the loading of particles on the bubbles and the loading phenomenon mostly took place above the feeding port. Behaviors of the profiles in these two zones were analyzed to reveal that a change in the feeding port placement or column height can, under some conditions, increase the overall bubble loading and thus, ultimately, the true flotation.