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To develop a disease forecasting system for effectively controlling wheat fusarium head blight caused by Fusarium graminearum, some epidemiological studies were conducted for two consecutive growing seasons in 2001-02 and 2002-03. On the basis of field experiments, the disease progress was determined on three wheat cultivars, namely Falat, Tajan, Zagros and one resistant line at Araghi-Mahalle Research Station in Gorgan. Disease index (DI) and various epidemiological models were employed to evaluate disease progress. The appropriateness for each model was evaluated by calculating Coefficient of determination (R2), and parameters of residual errors, including ME, CD, RMSE, EF and CRM. The Log-Logistic model, considered being the most appropriate model to describe disease progress on Falat, Tajan and Zagros under moist conditions. The resistant line did not show appreciable disease. However, under non moist conditions but artificial inoculation, Logistic was the most suitable model on Falat and Zagros with R2 of 0.86 and 0.91, respectively, while on Tajan, Log-Logistic (R2=0.79) was the most applicable model. Logistic and Log-Logistic were prefered as the most appropriate models to describe disease progress for FHB. This is the first report in which the above statistical parameters are collectively employed in describing temporal progress of a disease, as well as their importance in identifying the most appropriately fitted model.