中文摘要：

森林资源连续清查是我国获取宏观森林面积的主要手段，采用的是系统抽样方法。用理论分析的方法对样地森林面积计量3种不同确定方法的偏性与有效性进行论证。结果表明：1）连续变量法是无偏的，且效率最高；2）点定法也是无偏的，但效率较连续变量法低；3）优势地类法在某些情况下是有偏的，当总体单元的森林面积比例均接近于0或1时，结果接近无偏；4）本文结论表明，在遥感大样地调查中选择连续变量法是最合理的。

英文摘要：

Continuous Forest Inventory （CFI）is the main method to get the China’s forest area,which is conducted in a systematic sampling manner. In this paper,bias and efficiency of these three plot forest measurement methods will be proved by theoretical analysis. The result shows that：1. CV is unbiased,and it has the highest efficiency;2. PLB is also unbiased,but the efficiency is lower than CV;3. DLB is biased,however the population proportion of forest is almost 0 or 1 ,the result is nearly unbiased;4. CV method,which is unbiased and has high efficiency,should be chosen for remote sensing large-plot inventory.