Abstract: In order to observe the developing rule of the cockspur and test the differences of the cockspur length between two strains of the Erlangshan Mountain chicken. The cockspur length was determined once a week from 23 weeks age for at least 100 cocks among each strain， the primary result showed that there was no difference among individuals in each strain. Then the cockspur length was determined once a month from 27 weeks age，the results showed that the orderliness for the cockspur length among 2 strains was not so high and it was associated with the individual development and time，there was no association between cockspur length and body weight; the cockspur length for SD03 was longer than that of SD02. The result showed that the cockspur length can be used to distinguish the two strains，but it was difficult to use in practice.

Key words: Erlangshan Mountain chicken; cockspur; the length of cockspur