The effect of several collectors on the niobite synthetized under the condition of varying pH values and dosages were studied. The collecting property of several representative collectors was also investigated. The experimental result shows that diphosphonic acid is a good collector for niobite. Its recovery is about 84.24%-91.17% when the pH value of the pulp is less than 5.0 and the dosage of diphosphonic acid is 140 mg/L. The sequences of the selectivity and collecting capacity of the collectors were compared. Infrared absorption spectrum (IAS) and X-ray photoelectron spectroscopy (XPS) were used to detect and analyze the adsorption mechanism of diphosphonic acid on the surface of niobite. The IAS result indicates that diphosphonic acid is indeed adsorbed on the surface of niobite, and the XPS result shows that the binding energy of P_2p peak of niobite treated by diphosphonic acid has changed 2.85 eV. It confirms that the adsorption belongs to a chemisorption type.