The objective of this study is to show that cotton is a good incubation substrate for the Achatina fulica eggs. The egg incubation of Achatina fulica (giant African snail) on humidified absorbent cotton gave an average hatching rate of 71.09 %. It can thus be regarded as a good substrate for egg incubation of Achatina fulica following sawdust (90%). However the growth (weight) of snails during the five months of hatching was slow it was higher than the average of the starting (63.66g) .The study of the fungi contamination of eggs shows that the rate of contamination of unhatched eggs lies between 0.73 and 12.13 %. The contamination by Aspergillus Niger was highest at (12.13 %) and the weakest by Mucor sp. at (0.73 %) the percentages of appearance of fungi on unhatched eggs were as follows: Aspergillus Niger (40.74 %), Aspergillus terreus ((13.18 %)), Mucor sp. (2.46 %), Penicillium sp. (12.34 %)), Phoma sp. (18.51 %) and Trichoderma sp. (12.34 %). Mucor, Penicillium, Trichoderma and Aspergillus terreus were the least frequent and the least abundant. Among these moulds, at least two kinds (Aspergillus and Penicillium) were potentially toxinogenes