The number of reigns and the duration of years for the rulers of the Xia,Shang,and Zhou dynasties is a challenging problem in the chronology of these periods.This paper reconstructs the lin-eages of states such as Zhou,Qin,Lu,Qi,Song,Wei,Jin,Chu,and Zheng during the Spring and Autumn period by analyzing various chapters of the"Records of the Grand Historian."It finds a linear relation-ship between the practice of younger brothers succeeding older brothers and the average duration of each reign.Based on this relationship,the paper further derives the durations for the Western Zhou and Shang dynasties,revealing results that closely align with the records in the"Ancient Bamboo Annals."The pa-per suggests that the lineage of the Xia Dynasty in the"Records of the Grand Historian"may lack docu-mentation regarding the practice of younger brothers succeeding older brothers,which could explain the observation in the"Ancient Bamboo Annals"that each Xia king reigned for over thirty years.