Self-phosphating organic coating is a novel finishing technology that can be prepared by predispersing an optimal amount of phosphatizing reagent in the paint formulation. Fourteen phosphate compounds, including different forms of phosphoric acid, phosphonic acid, ester phosphoric acid, or ester phosphonic acid, were tested for their possible use as in-situ phosphatizing reagents (ISPRs). The cold-rolled steel (CRS) panel was soaked in a dilute solution of 0.5-10 wt % phosphate compound in a solvent mixture of butyl carbitol and 2-propanol and then baked at 325 degrees F for 10 min. The nature of chemical bonding, surface/interface morphology, and elemental composition of metal phosphate formed at the CRS surface was probed by 80 degrees grazing angle FTIR and SEM-EDS techniques. The results are summarized as follows : (1) organic phosphatizing reagents are more dispersible in in-situ phosphatizing coatings (ISPCs) and can become very effective ISPRs; (2) the nature of metal phosphate bondings in ISPCs is via an acid-base type interaction, PO--Fe2+, rather than an induced dipole interaction of P=O/Fe complex type; (3) ISPRs containing polymer chains may be good as coating adhesion promoters, but some of them are not very reactive with metal surfaces; they are also not effective as in-situ phosphatizing reagents; (4) water in ISPRs can accelerate the metal surface phosphatization; and (5) the ISPRs/amine complex can provide a long pot life of ISPCs while giving an identical in-situ metal surface phosphatization as the uncomplexed form of ISPRs. The feasibility of using organic versus inorganic ISPRs in the ISPCs will be compared and discussed.