Antimonite precipitation was used to detect Ca² in the stigmas and styles of lettuce (Lactuca sativa) before and after pollination. Abundant calcium precipitates were detected in the papillae walls on the receptive surface of the stigma both before and after pollination. Meanwhile, few calcium granules were observed in the wall of epidermal cells on the non-receptive surface. Before pollination, calcium formed a gradient from the top to the base of the style in the transmitting tissue and parenchyma cells. After pollination, calcium levels increased in the transmitting tissue, and the gradient distribution became stronger. The calcium gradient was also observed in the tracheae of the vascular bundle of the style. These results indicate that a calcium gradient exists in the lettuce style, and that pollination induces an increase in stylar calcium levels.