Abstract: The steady thermal-hydraulic analysis for tubebundle region including primary separators of CPR1000 steam generator was done by three-dimensional software GENEPI. The results show the flow mal-distribution of the tube-bundle and primary separator regions, and the primary separators in the central and hot side bear a larger load. The analysis can be used as the input of the moisture analysis of separators and dryers. The calculation results of different local pressure-drop coefficients of the primary separator were also compared. The results show that the larger the coefficient is, the more uniform the flow distribution is.