Based on the Cloud-Radio Access Network (C-RAN) structure and massive Multi-Input Multi-Output (MIMO), we propose one comprehensive system model and give the Energy Efficiency (EE) analysis of this system. The C-RAN structure is amended for better antenna control in massive MIMO based C-RAN system model. Furthermore, system EE optimization problem is modeled from a comprehensive way, and its solution is addressed with a convex optimization method plus an offline decision. In EE analysis, apart from the prior literature, Carrier Capacity (CC), antenna, Radio-Frequency (RF) chain, machine room and also the electron circuits are integrally taken into consideration. A positive correlation is observed between CC and the EE performance prior to the optimal value, after this optimal value, further increase CC has little help to EE enhancement.