TY - JOUR AB - Purpose– The purpose of this paper is to apply grey system theory to population system and project China's population.Design/methodology/approach– The paper applies the GM(1,1) model to China's population projections. Two key aspects of the method are crucial for obtaining best accuracy of prediction. They are the choice of the length for the original data to be used in the model and the adoption of the GM(1,1) metabolic model in prediction. The former determines what initial data to be used while the latter describes an iteration process on how to proceed to predict.Findings– The results show that in 2015 China's population will reach 1.37 billion and in 2050 it will be between 1.42 and 1.48 billion, which is in accordance with the latest projections from the UN. The findings show the GM(1,1) metabolic model is an effective mathematical means in population projections.Research limitations/implications– The paper suggests that GM(1,1) metabolic model can provide an effective simulation model for complicated systems with uncertainty and can be used in many fields.Practical implications– The paper provides useful advice for the department of population.Originality/value– Most population projections have been based on assumptions about fertility, mortality, and migration. The paper considers the population system as a grey system and introduces the GM(1,1) metabolic model to population projections. VL - 38 IS - 3/4 SN - 0368-492X DO - 10.1108/03684920910944119 UR - https://doi.org/10.1108/03684920910944119 AU - Caimei Lu AU - Yonghong Hao AU - Xuemeng Wang ED - Mian‐yun Chen ED - Yi Lin ED - Hejing Xiong PY - 2009 Y1 - 2009/01/01 TI - China's population projections based on GM(1,1) metabolic model T2 - Kybernetes PB - Emerald Group Publishing Limited SP - 417 EP - 425 Y2 - 2024/04/25 ER -