The principal development that has taken place in the past years is embodied in the title immunohistochemistry. The change from fluorescent-antibody methods to enzyme-antibody conjugate is necessitated by changes brought about by a single advance which has produced a minor technological revolution. In immunohistochemistry demonstrating of enzyme-antibody conjugate plays an important role. We have compared two conjugation procedures, the one-step method and two-step method with glutaraldehyde as a cross-linking agent as these novel methods are simple and fast which does not suffer from any cross reactions.. The enzymatic and staining characteristics of both the conjugates were evaluated. HRP was use as an enzyme with AntiHela as a monoclonal antibody. All the conjugates showed positive reaction with Hela cells stained as brown granular deposits but did not show any reactivity with others. The panel of malignant tissues against which the conjugates were tested revealed a strong reactivity with yellow-brown color in the nuclear region of the malignant cells. However the contrast of the staining was more marked when two step conjugate was used and the molecular weight of it was lower than that of the one-step conjugate. One- step glutaraldehyde method was cheapest as compared to other and time of preparation is also less. The results have led us that conjugate was the backbone and preparation must be of great attention.