Microbes within a mixed culture systems function as a whole, based on complicated interrelationships and population dynamics.It is challenging to separately characterise each species involved in the microbial ecosystem.Howevcr, synthetic microbial ecosystem, which is delicately designed with clarrified genetic background and interspecies relationships, has exhibited great advances in simplifing bacterial consortia and in elucidating the mechanism of ecologial and evolutionary dynamics.In the present study, we designed a synthetic ecosystem by using two quorum-sensing signal transduction circuits (RhlI/R andLuxI/R) to self control the population dynamics of the consortia under ehangable environmental factors.This synthetic microbial ecosystem provides valuable information for addressing questions in analyzing and malipulating mixed cultures, and it may act as a chassis for construction of more complex microbial ecosystems for industrial applications.