Abstract: In the period of 1957—1959, cultivation of strains Ce5, Ce5-5-1, Ce5-29-1, and Ce10-4 of Claviceps microcephala (Wallr.) Tul. on different hosts was carried out and factors influencing the alkaloid contents during process of cultivation were studied. It was experimentally proved that time of inoculation correlates with alkaloid production. The ergots from inoculations made during flowering stage produced more alkaloids than those from inoculations made 3—5 days prior to flowering. As basic fertilizers, stable manure plus certain amounts of NPK enhanced alkaloid production markedly while poor results were obtained with stable manure alone.However, no effect was observed with any catch fertilizers. Gibberellin, 2-4D, sodium-naphthyl acetate, and colchicine were either used as foliage sprays or mixed with spore suspensions. No effect on alkaloid production was detectable whatsoever. All these compounds except gibberellin reduced infection to different levels. Alkaloids were detectable in young sclerotia as early as 15 days after inoculation. Maximum contents were reached five weeks after inoculation and no increases were obtained thereafter. Cultivation on second rye crop in the same year proved successful. Both amount of infection and alkaloid contents of the resultant sclerotia were comparable to those produced on first crop. Variation of alkaloid contents due to different localities remained inconspicuous. Slightly lower contents were obtained from ergots cultivated in Hangchow as compared with those in Harbin and Peking. Variation of alkaloid contents due to different years was also observed; for example, alkaloid contents of ergots produced by Ce5 on variety Changpei in 1957 were higher than those in 1958 and 1959.