The main objective of this research was toquantify and predict the time and seed germination pattern of Onobrychisscrobiculata, Onobrychis subnitens and Vicia variabilis species using thermal,hydrotime and hydrothermal time models. In addition, the habitat properties ofspecies, growth rate, viability and physiological response of species indifferent soil water potential and temperature were studied. The species, growth rate, survival and physiological response of specieswere studied in different states of soil water potential and temperature. Themost important physical and chemical characteristics of the soil as well asimportant plant characteristics were measured in the habitats of each species. For seed germination modeling, a completelyrandomized design with three factors (plant species, temperature and waterpotential) and four replications was used. In order to study the p h ysiological traits, the growth and survival of the species under theinfluence of drought stress and evaluation of their seedling survival indelayed culture of the collected seeds from the field were cultivated in thepot in a completely randomized design. Four irrigation treatments were carried outfor each autumn and spring season. In each pot, the percentage of growth(seedlings reached the surface of the soil) and at the end of the growingseason, the percentage of live plant (percentage of plants survived until theend of the growing season) was calculated. In order to study the growth under naturalconditions in the research station of University of Kurdistan, direct plantingwas carried out in a randomized complete block design in two autumn and springseasons and percentage growth and at the end of experiment the percentage oflive plant were calculated. The data from the experiments were analyzed usingthe ANOVA and Duncan's test. The results showed that the habitats of O.scrobiculata have an average rainfall of 388 mm, mean annual temperature of 12.4 ° C, andshallow soils with moderate soil texture, in the range of 1350-1620 melevation. This plant has 611 Kg/ha production and has a lot of coldresistance, but its resistance to drought is moderate. The base,optimum and maximum temperatures of seed germination were 5.5, 18.8–19.76 and38.14°C, respectively. The thermal time was 25.87 degree-days. O.subnitens with 1397 Kg/ha production growth in habitats which have 1720-1940 m elevation,354mm rainfall and 10.6 mean annual temperature in In relatively shallow soilswith heavy oil texture. O.subnitens is resistant to frost and drought and has a high germination percentage. Thermaltime required for 50% germination was 21.29 degree-days. The base, optimum, andmaximum temperatures were 1.23, 17.22 and 41.10°C, respectively. The habitat of V.variabilis with an average annual rainfall of 542 mm, the average annual temperatureof 12.5 ° C, has relatively high depth soils. Despite thegood frost resistance, it has little resistance to drought. The base, optimum, and maximum temperatures of V.variabilis seed germination were -1.2, 20 and 35.13°C, respectively. The thermal timerequired for 50% germination was 60.9 degree-days.The final result is that the O.subnitense have a higher percentage and rate of germination than the other twospecies, and, on the other hand, has the lowest hydrotime coefficient, so it ismore resistant to drought in the germination stage than the other two species. Due tothe fact that species with higher rate and germination percentage can be moreresistant to winter frost, it can be concluded that O.subnitense is one of the cold resistant anddrought tolerant species. Theresults of pots and field studies also confirm the higher percentage of growth,survival and production of O.subnitense. Accordingly, O.subnitense issusceptible in pastureimprovement programs in vegetative area and other habitats which are similar inecological conditions. Keywords: Sainfoin, Drought stress, Vetch,Modeling, Range