Abstract: Angle indexwas used to identify tree spatial distribution patterns of natural Korean p ine broad-leaved forest, while modelswere emp loyed to fit the relationship s between the number of samp ling points and p robabilities thatthe identified tree spatial patterns coincide with the actuality, and then the number of samp ling points atwhich thesecondary derivatives of the fitted equations began to app roach 0 was determined as the minimum samp le for spotchecking tree spatial distribution patterns of this forest. To further validate the rationality of the minimum samp le,data from 9 simulated p lots and 2 Ecuador natural forest p lotswere also analyzed. It showed that the minimum samp le for spot checking tree spatial distribution patterns of natural Korean p ine broad leaved forest should be 49.