Quantitatively self demographic effects of Chinese population transition show that demographic effects on quantity will persist for a long time, and the positive or negative effects on age-structure will undulate and wither away in the end. The Chinese population transition and the intended low fertility in the future will jointly bring on the level of age increase, demographic dividend change, and the other demographic variables. As a Chinese population strategy, the attention should be paid to self demographic effects on quantity and age-structure, and the moderate low-fertility should be kept in China at present and in the future.