The artificial rearing of mussel spats has already been employed for productivepurpose. Scale of production is steadily expanding and the yearly output and numberof crops harvested are also increasing steadily. At present, it is estimated that a smallscale productive operation would call for as many as 5×10~9 to 1×10~(10) healthy eggs.So it is imperative that the understanding on breeding habits and the techniques governing the collection of mussel eggs should be thoroughly grasped. In Qingdao we use in spring the various stimuli, including air-drying, mechanicalshaking, byssus drawing, temperature raising and by stimulating the reproductive cellsof opposite sexes, etc. to induce the mussels to ejaculate. Of these, water temperatureraising seems the most favorable and highly effectite (table 1).Usually 60% to 100%of the individuals eject. In autumn, however, this method usually worked not so well as in spring unlesssome natural prerequisites would be satisfied such as a fall of temperature and rainingduring the springtide period ect. (Table 2). Nevertheless, a better result could beattained by lowering the temperature as a stimulus. The parent mussels at first werereared in the artificially flowing sea water of low temperture (8-12℃) for 8-10hours and then put back to the sea water of normal temperature (18℃). Under suchconditions 40% of the individuals could be induced to eject. Experiment conducted on more than 9400 mussels showed that among the 1.5and 2-year-old mussesls the sex ratios of male and female in ejection were 54.4% to45. 6%. This was not perfectly agreed with the sex ratio in natural population. (10) The quantity of eggs collected from the different age groups and in differentseasons, differs greatly. The average number of eggs collected from the 2-year-oldmussels was about 8 million pieces. The ratios of eggs collected among mussels of 1-year-old, 1.5-year-old and 2-year-old were approximately as follows: 1: 4.3: 16.9(Table 5). Mussels of the same age group produced more eggs at the time shortlybefore the reproductive season than in the blooming stage of the reproductive season orin its later stage (Table 6). The 1.5-year-old autumn mussels produced more eggsthan the spring mussels, which have passed through twice the growing period of"spring-summer-winter" (Table 5,6). Based on the above findings, we were enabled tomake out a more reasonable program for theacollection of mussel eggs on a productiveseale.