The present invention dicloses to a method of producing a Lactuca plant seed including using a Megachile bee as pollination means, and providing the a Megachile bee a minor nectar plant to have preference in flower visiting, in addition to a pollen parent Lactuca plant and a seed parent Lactuca plant and to perform a crossing of a Lactuca plant using a plant species having the preference in flower visiting equivalent to or lower than that of the Lactuca plant. According to one embodiment of the present invention, it is possible to produce a Lactuca hybrid plant seed more efficiently and economically than before while using a Megachile bee as pollination means.