Abstract:This paper systematlly deals with the applied theory and method of angle measuring in volume growing estimation in permanent point sampling. A new estimator of basal area and volume increment is introduced by measuring reserved trees. Thus the new dynamic monitoring method of system is built based on the estimator. The results show that the methods suggested by author not only improve the traditional method but also eliminate the phenomenon of zero and jumping in the estimation of basal area and volume increment. Meanwhile the theoretical results also show the principle of methods no difference between varing angle ratio and measuring growth of reserved trees in Permanent point sampling.