The first version of the NUIST model, NUIST- ESM V1 was released in April 2014, which is a climate system model that couples atmosphere, land, ocean, and sea ice components. The NUIST ESM V2 version will be ready for release by the end of 2015. This V2 version will be used to participate in IPCC AR6. The current V2 model consists of a modified version 5.3 of ECHAM (the European Centre Hamburg Model) atmosphere and land models, the version 3.4 of NEMO (the Nucleus for European Modelling of the Ocean), and an improved version 4.1 of the Los Alamos sea ice (CICE) model. Improved physical parameterizations were incorporated into the atmosphere, land and sea ice components of the V2 model for better climate simulations. Besides, the upgraded coupler is more computationally efficient and energy (flux) conserved. Comprehensive and quantitative metrics are set up for evaluation of the model performance against observations and comparison with the CMIP5 models. The assessment metrics include more than 50 characteristic variables describing climatology and modes of climate variability in the earth climate system.