Abstract: In the present study the effect and survival of Bacillus spp. (Bacillus subtilis and B. cereus) in milk samples that were collected from Khartoum, Khartoum North and Omduraman were studied. In order to evaluate the degree of spoilage by those organisms, sterile milk sample were inoculated by 3.1x10³ cfu mL^-1 of B. cereus and 3.5x10³ cfu mL^-1 B. subtilis and stored at 7, 12, 21, 37 and 45°C. The milk samples were investigated daily for total bacterial counts, fat %, protein % and acidity. The present results revealed that Bacillus spp. inoculated in milk samples showed significant differences for protein, fat, acidity and bacterial count (p<0.05) at different storage periods and temperatures. Moreover the milk samples showed a shelf life of more than 5 days at 7 and 12°C. However, the milk samples that stored at 21, 37 and 45°C recorded a shelf life of 1-4 days.