The　rapid　development　of　urban　agglomerations　has　endangered　the　eco-environment.　It　is　critical　to　research　the　coupling　coordination　between　the　eco-environment　and　urbanization　to　promote　regional　sustainable　development.　The　aim　of　this　study　is　to　investigate　the　coupling　coordination　degree　(CCD)　between　the　eco-environment　and　urbanization　in　the　MRYRUA　and　to　identify　the　key　factors　influencing　the　CCD.　Based　on　the　remote　sensing　perspective,　this　study　used　the　remote　sensing　ecological　index　(RSEI)　and　comprehensive　nighttime　light　index　(CNLI)　to　measure　the　eco-environment　and　urbanization　level　of　the　middle　reaches　of　the　Yangtze　River　urban　agglomeration　(MRYRUA).　Then,　based　on　the　CCD　model,　the　relationship　between　the　eco-environment　and　urbanization　was　evaluated.　The　geographical　detector　was　utilized　to　analyze　the　key　factors.　The　results　showed　the　following:　(1)　both　the　ecoenvironment　and　urbanization　of　the　MRYRUA　show　a　fluctuating　upward　trend,　and　the　change　rate　of　urbanization　is　greater　than　that　of　the　eco-environment.　(2)　The　overall　coupling　level　of　the　MRYRUA　changes　from　moderate　unbalanced　coupling　to　moderate　balanced　coupling,　and　the　distribution　of　the　CCD　presents　spatial　imbalance.　The　coupling　level　of　the　central　region　is　higher　than　that　of　the　peripheral　cities,　and　the　coupling　level　of　the　provincial　capital　cities　is　higher　than　that　of　other　cities.　(3)　The　explanatory　power　of　socioeconomic　factors　in　the　CCD　is　higher　than　that　of　natural　factors　in　the　single-factor　detection;　urban　green　space　(UGS)　plays　the　most　significant　role　in　the　interaction　detection.　(4)　RSEI　has　a　negative　correlation　with　the　CCD,　while　the　CNLI　has　a　positive　correlation　with　the　CCD.　The　development　of　urbanization　has　played　a　decisive　role　in　the　CCD.　The　results　provide　a　scientific　foundation　on　which　the　MRYRUA　can　achieve　sustainable　urban　development.