Chondrus is an economically important red algae widely used for food and biochemical pur- pose. It early development is crucial for the culture and seedling propagation. We chose tetraspores and car- pospores of Chondrus ocellatus as examples for experiment of the culture, induction and release in laboratory condition, aiming to understand early development of C. ocellatus and to apply in seedling production. Ma- ture C. ocellatus were collected in Qingdao, China, from Nov. to Dec. 2004. After the gametophyte and tet- rasporophyte were brushed and washed with sterilized seawater, the algal materials were treated in 1.5% KI for 20 min, then were dried for 1h to stimulate the releasing of spores. After the spores released overnight, it were cultured in PES medium, incubated at 18 ℃, 10±2 μmol/(m2·s1) in 12:12h (light: dark). The observation and recording under microscope were carried out. Continuous observation of the early development showed that both tetraspore and carpospore are similar to each other. In general, three stages of the early development were shown being division, discoid crust and seedling stages. To the division stage, the most obvious feature was the increasing of cell number; during the discoid crust stage, the discoid crust had a three-dimensional axis, and it began to differentiate into two types of cells: the basal cells and the apical cells; and to the seed- ling stage, several protuberances-like appeared on the discoid crusts and formed juvenile seedlings. Carpo- spores and tetraspores exhibited a similar development process that included division stage, discoid crust stage and seedling stage. Chondrus is an economically important red algae widely used for food and biochemical pur- pose. It early development is crucial for the culture and seedling propagation. We chose tetraspores and car- pospores of Chondrus ocellatus as examples for experiment of the culture, induction and release in laboratory condition, aiming to understand early development of C. ocellatus and to apply in seedling production. Maurette C. ocellatus were collected in Qingdao, China, from Nov. to Dec. 2004. After the gametophyte and tet- rasporophyte were brushed and washed with sterilized seawater, the algal materials were treated in 1.5% KI for 20 min, then were dried for 1h to stimulate the releasing of spores. After the spores released overnight, it were cultured in PES medium, incubated at 18 ° C, 10 Continuous observation of the early development showed that both both tetraspore and carpospore are ± 2 μmol / (m2 · s1) in 12: 12 h (light: dark). similar to each other. In general, three stages of the early development were shown as division, discoid crust and seedling stages. the most obvious feature was the increasing of cell number; during the discoid crust stage, the discoid crust had a three-dimensional axis, and it began differentiable into two types of cells: the basal cells and the apical cells; and to the seed-ling stage, several protuberances-like appeared on the discoid crusts and formed juvenile seedlings. Carpo- spores and tetraspores exhibited a similar development process that included division stage, discoid crust stage and seedling stage.