It was verified that sporogenesis in B. licheniformis, strain 2390, occurs only when Mn[2+] or Mg[2+] is present in a synthetic medium in the rates of 0,1mg% or 1,0 mg%. Both these ions stimulate the growth of the culture and after 14 days of incubation, endopores and free-spores were found in the medium, in which metals concentrations were of 0,1 mg%. Using higher concentrations of Mn[2+] or Mg[2+] such as 1,0mg%, free-spores were obtained after 10 days incubation. Other ions tested like, Ca[2+], Fe[2+], Co[2+], Cu[2+], Mo[6+], Zn[2+] and B[3+] did not influence the process. Co[2+] and Cu[2+] were toxic, inhibiting culture's growth. The ion Ca[2+] seemed not to interfere in sporogenesis, but was able to inhibit culture's growth at a concentration of 3,0 mg%. Correlation between the rate of glucose and the time of sporogenesis of B. licheniformis was found in strain 2390, when Mn[2+] was 1,0 mg%. The critical glucose concentration was about 12,5% of the total amount added initially to the culture media. The author also suggests the possibility of dipicolinic acid synthesis being activated by Mn[2+] and Mg[2+].