This study concerns with the role of corrosion product deposition in microbial corrosion between zinc and its alloys buried in the soil and soil microbes such as S.aureus, Streptococcus, B. subtitles, Lactobacillus, Proteus, Corynebacterium, Pseudomonas, A.niger, Mucor and Desulphovibro sp and also about inhibition by using plant extracts of Neem and Hibiscus which have phytochemicals like flavonoids and alkaloids that detecting by using techniques such as weight loss and thermodynamic studies. Langmuir and Freundlich, Temkin and Florry-Huggins models are employed to analysis adsorption occurred in the experimental data of adsorption isotherms. The Freundlich, Langmuir and Temkin models are employed to analysis adsorption occurred in the experiment.