Abstract: The seed coat trait of Cucurbita pepo was classified into two types, seed-hulled and seed-naked. Experiments were performed to study the inheritance pattern. Three inbreeds with hulled seed, 04FC409-4, 03N-122-19 and 04LAg-26-2, and three inbreeds with hull-less seed, 04GD112-7, 1N-275-7 and 04LAg-26-28, were used as the parental lines in the mating patterns 04FC409-4 and 04GD112-7, 03N-122-19 and 1N-275-7, 04LAg-26-2 and 04LAg-26-28. In the F₁ generations, all the plants were seed-hulled. However, in the F₂ generations, segregation of hulled and hull-less seeds showed the ratio of almost 3 to 1. For the backcrosses, all the BC₁ and F₁ (the inbreed with hulled seed used as recurrent parent) generations appeared seed-hulled. But in the BC₂ and F₁ (the inbreed with hull-less seed as recurrent parent) generations, segregation of hulled and hull-less seeds showed the ratio of almost 1 to 1. So it was concluded that each of the hulled seed and hull-less seed in C. pepo was controlled by one pair of different nuclear genes and “seed-hulled” was dominant to “seed-hull-less”.