Hard seed, also classified as physical dormancy, is very common in forage legumes (Baskin and Baskin 2004). Many methods, based on scarifying seed coat have been developed such as mechanical scarification, chemical scarification to soft hard seed (Baskin and Baskin 1998). Hydrotime is a way to describe the relationship between water potential (Ψ) and seed germination rates and percentages (Bradford 1990) The hydrotime model has proven to be useful for understanding the physiological mechanism of seed germination and has been suggested as a tool to describe seed germination time in relation to water condition (Alvarado and Bradford 2002). Generally, the effect of water condition on legume seed germination was evaluated on seeds after dormancy was broken. However, the way various treatments affecting seed response to water potential and the ecological significance of the response is less well understood (Zuk-gołaszewska et al. 2007). This study aimed to test the effect of sulfuric acid scarification on hydrotime model parameters of Vicia angustifolia