The study assessed an antimicrobial effect of coating by an addition of herb extracts to maintain the quality of pork balls as a food model. Five herb extracts, namely green tea extract, mangosteen extract, turmeric extract, guava leaf extract and cinnamon extract were studied antimicrobial activity against all three pathogens; Escherichia coli, Staphylococcus aureus and Aspergillus sp., and also to investigate an application of herb-extracted coating, the shelf life of pork balls were evaluated the pathogen The results showed that green tea extracts inhibited E.coli with the widest zone, and inhibition. mangosteen extracts could inhibit all tested pathogens. For the further experiment on herb-extracted coating application, uncoated pork balls an pork balls coated with control coating (no herb-extracted contents) had no significant differences (p>0.05). The number of Total Plate Count continuously increased by 2 log cfu/g throughout 15 days storage, leading to spoilage. As for pork balls inoculated with E.coli, the coating containing green tea extracts and former coating containing food additives showed significant reduction of about 1.5 log cfu/g lower E.coli count (p 0.05); this maintained the shelf life of products. Pork balls with inoculated S.aureus had no significant numbers between coated and uncoated pork balls, whereas among this group mangosteen gave the best result of S.aureus inhibition. It was clear that Aspergillus sp, presence in coated and uncoated pork balls had non-significant difference (p o.05), as numbers increased to 6 log cfu/g during storage. In general, the effect of herb-extracted in coating can specifically affected E.coli growth and extended the quality of coated balls. This can be possibly applied to improve shelf life of other foods product.