Poly(epsilon-L-lysine) (epsilon-PL) is an unusual biopolymer composed of L-lysine connected between alpha-carboxyl and epsilon-amino groups. It has been used as a preservative in food and cosmetics industries, drug carrier in medicines, and gene carrier in gene therapy. Modern biotechnology has significantly improved the synthetic efficiency of this novel homopoly( amino acid) on an industrial scale and has expanded its industrial applications. In the latest years, studies have focused on the biotechnological production and understanding the biosynthetic mechanism of microbial epsilon-PL. Herein, this review focuses on the current trends and future perspectives of microbial epsilon-PL. Information on the screening of epsilon-PL-producing strains, fermentative production of epsilon-PL, breeding of high-epsilon-PL-producing strains, genomic data of epsilon-PL-producing strains, biosynthetic mechanism of microbial epsilon-PL, and the control of molecular weight of microbial epsilon-PL is included. This review will contribute to the development of this novel homopoly(amino acid) and serve as a basis of studies on other biopolymers.