Sainfoin (Onobrychis viciifolia Scop.) is a perennial forage legume has recognized for its feed value and high stability. This experiment was conducted to investigate the relationship among morphological and agronomic traits using multivariate statistical methods including correlation, regression and factor analysis. Twenty one accessions of Sainfoin were evaluated in a randomized complete block design with 6 replications during 2008 and 2009. Analysis of variation showed that there was significant variation for forage yield and its components. Results indicated that dry yield was positively correlated with fresh yield, stem percent and number of stem per square meter while it was negatively correlated with flowering date, leaf percent and leaf to steam ratio.Forage yield had no correlation with plant height but plant height was correlated with number of stems per plant (as a component of forage yield). The result of path analysis indicated that number of stem per plant, stem percentage and plant height had the most direct and positive effects on dry matter yield.On the basis of stepwise regression analysis, stem percentage and plant height justified the majority of dry matter yield variation and can be used for indirect selection of forage yield. Factors analysis identified five hidden factors which justified more than 75 percent of the total variation. Results indicated that there was a wide genetic diversity for forage yield in this germplasem and indirect selection based on number of stem per meter square, stem percentage and plant height would be effective for improving forage yield.