The experiments were carried on the coastal region of Putou Island from December.18.1963 to the middle of May 1964. For every 15 days or one month we put down inthe sea one net or two to which the natural spores would attach, then we observedthe appearance, growth and reproduction of the buds. At the same time, we put thethallus on the glass slide in the vessels to liberate the spores. After two days wesurveyed the germinating condition and form of the liberated spores. The experimental results are as follows: 1. The life history of Porphyra yezoensis Ueda cosists two stages, sexual repro-duction and asexual reproduction. The sexual reproduction begins from December to late March or early April. Theneutral spores begin to appear in the plant which is more than one cm to 10 cm inlength, but not in the plant less than 0.7 cm. The sexual reproduction begins from late December to June are early July. The car-pospores are liberated continuously until the plants disappear. The results correspondwith Kurogis (1961) report. 2. The period which the spores adhere to the nets is long. According to tableI, it is from December to early April in general.But we put down the nets earlier,the plants will grow longer and the products will be richer. Therefore the suitabletime for the spores to adhere to the nets is December or January. 3. At the first crop, according to the table 3, every square metre produced an average of 0.5 catty in dry weight.If we put down the nets in the middle ofDecember, and begin to cut in the early April then we may have 3-4 harvests andthe production will be increased greatly. Therefore this method for cultivating Porphyra yezoensis Ueda has an economic significance in the Chekiang region. 4. The time of the appearance of the neutral spores is comparatively long. Inthe course of our research on the reproduction of Porphyra yezoensis Ueda, it isknown that they play an important role in increasing the young buds in cultivation.This problem is worthy to be considered and must be settled, and thus we shouldutilize the neutral spores in the cultivation of the Porphyra yezoensis Ueda to theutmost.