中文：

PMI是指采购经理指数，是一组经济指标，用于衡量制造业在特定时期的景气程度。该指数是由美国采购管理协会发布的，包含一系列的指标，如新订单、库存、价格、就业、供应商交货等。这些指标的值通常以百分比形式表示，并经过季节性调整以消除季节性因素的影响。

PMI指数在50%以上为增长一般认为是好的，如果低于50%则表明经济活动在减少。PMI指数对于预测经济走势有一定的指导意义，尤其是在短期内预测GDP的变化。此外，PMI指数还可以用于预测企业的生产和销售情况。

PMI指数的应用非常广泛，不仅可以用于国内经济分析，还可以用于国际贸易分析。PMI指数已经成为全球范围内最重要的经济指标之一，对于企业和政府决策具有重要意义。

英文：

PMI, or Purchasing Managers' Index, is a group of economic indicators used to measure the degree of prosperity of the manufacturing industry in a specific period. The index, which is published by the Institute for Supply Management in the United States, includes a series of indicators such as new orders, inventory, prices, employment, supplier delivery, etc. The values of these indicators are usually expressed as a percentage and adjusted seasonally to eliminate seasonal effects.

A PMI index above 50% is generally considered positive, indicating that economic activity is increasing, while a PMI index below 50% indicates a decrease in economic activity. The PMI index has certain guiding significance for predicting economic trends, especially for short-term predictions of GDP changes. In addition, the PMI index can also be used to predict the production and sales situation of enterprises.

The application of the PMI index is very wide, not only for domestic economic analysis, but also for international trade analysis. The PMI index has become one of the most important economic indicators in the world, which is of great significance for enterprise and government decision-making.