本文通过对四川宁南县钟家梁子遗址人骨样品的C、N稳定同位素分析，探索该遗址及金沙江中下游地区先民的食物结构和生业经济。结果显示，钟家梁子遗址先民的δ¹³C值范围为-18.4‰~-10.0‰，δ¹⁵N值范围为4.76‰~12.63‰，表明其食物结构中C₃、C₄类食物均占有一定比例，且摄入了较多的动物性蛋白；不同性别、年龄及葬俗的群体间存在食谱差异。结合当地的自然环境及相关考古成果，推测钟家梁子遗址先民从事稻/粟混作农业，并通过采集野生植物进行补充；对动物资源的利用具有多样性，渔猎及家畜饲养均占有重要地位。通过对金沙江中下游地区相关研究的进一步梳理，发现该地区新石器时代晚期至青铜时代的作物结构一直以稻/粟混作为主，青铜时代开始种植小麦、大麦、大豆等作为补充，对植物资源的利用越发灵活和多样化。此外，该地区不同遗址的经济结构存在较大差别，可能受到了自然环境、地形阻隔、人群交流及当地文化传统等因素的影响。

In this paper, stable isotope analysis of carbon and nitrogen was carried out on human bones from the Zhongjialiangzi site, in order to reveal the dietary structure and subsistence economy of the ancestors of the site. Combined with relevant research, the economic pattern and adaptation strategies of the ancestors in the middle and lower reaches of the Jinsha River from the late Neolithic period to the Bronze Age were explored. The results showed that the δ¹³C value range of the ancestors of Zhongjialiangzi site was -18.4‰~-10.0‰, and the δ¹⁵N value range was 4.76‰~12.63‰, indicating that C₃ and C₄ foods accounted for a certain proportion in their food structure, and their trophic levels were high. It is worth noting that with the change of time, the distribution range of the δ¹³C value of the ancestors gradually decreased, and the δ¹⁵N value also had a tendency to decrease, which may be related to the further development of agricultural economy. Furthermore, there were differences in diets between different genders, ages and burial groups, it may be related to their status and role in society, or to the movement of people. In addition, the δ¹⁵N values were significantly higher in subadults than in adults, which may be related to breastfeeding and suggest that the ancestors of the site were cared for by adults in their early years. Combined with the local natural environment and relevant archaeological achievements, the ancestors of the Zhongjialiangzi site may have mainly engaged in rice and millet mixed agriculture, which was supplemented by collecting wild plants. The use of animal resources is diverse, fishing, hunting and livestock breeding all played an important role. Through further combing of the subsistence economy in the middle and lower reaches of the Jinsha River, it is found that from the late Neolithic period to the Bronze Age, the agricultural structure of the area was mainly mixed with rice and millet. Compared with the rice-based agriculture in the Anning River Basin and the agricultural structure of rice, wheat and millet mixed cropping around Fuxian Lake, the agricultural structure of this area had its own uniqueness. Furthermore, a small amount of soybeans and wheat began to be cultivated as supplements in the Bronze Age, indicating that the ancestors became more flexible and diversified in the use of plant resources. In addition, there are great differences in the agricultural structure of different sites, which may be caused by environmental differences in different regions, and may also be affected by factors such as topographic barriers and cultural traditions.