【摘要】On the occasion of the 20th anniversary of Chinese Journal of Population Science starting publication,the editorial board of the journal invited scholars to have conversations by writing about "frontier issues of population studies and other disciplines",which are expected to be informative for readers.These conversations include "Low costs industrialization and half-completed urbanization must be ceased in order to systematically solve rural migrant workers ' problems" by Gu Shengzu,"Policy suggestions for increasing the proportion of mid-income people" by Li Peilin,"Income distribution and harmonious society" by Li Shi,"A general survey and comment on the 20 year reform of the social security system" by Zheng Bingwen,"An urgent need for studying on and monitoring current fertility rate" by Guo Zhigang,and "Retrospect and prospect on the development of China 's population science" by Zhai Zhenwu.