Abstract: The comparative anatomy of the leaves of 21 species and 5 varieties of the genus Picea has been investigated with special reference to their resin canals. Resin canals are found in the needles of all Picea species under study. They are always arranged in longitudinal series, mostly being interrupted by transverse partitions of mesophyll except in a few species where they exhibit two disinterrupted canals. The number of the canal segments in a needle is quite variable in different species, and even in different needles of the same species. Their arrangement, according to the frequency of the occurrence of two-canals, one-canal and no canal in the middle transection of the needles and from the observation of the clearing specimens, can be classified into four groups (fig. 1). It would seem preferable that the characteristic difference of the resin canals, which might be of texonomic importance, lie in their discrepancy in the relative distribution of the resin canals rather than in the number or the relative length of the canals in each needle. This study also suggests that those with two canals lying along the lateral angles of the needles might be considered as the primitive types, from which other forms have been derived. Long canals may be broken into short cystic segments or subsequently degenerated into residue canals located only on one side of the needles.