A high-molecular-weight aspartyl proteinase complex, sensitive to pepstatin A was purified to near electrophoretic homogeneity from dry seeds ofjack pine (Pinus banksiana, Lamb.). Two partial activities, endo-and exo-proteinolytic, were associated with the complex, judged by the analysis of haemoglobin hydrolysis products. The high activity of this enzyme in dry jack pine seed suggests a possible function in early germination.