Eighty four human maxillary second premolars were injected with china. ink, decalcified, cleared and used in study, in vitro, to determine the number of root canals, the frequency and location of lateral canals, the frequency and location of transverse ansatomoses, the curvature of root canals, the location of apical foramens, and the frequency of apical deltas. The results were as follows: 1. Most of the teeth demonstrated one canals, but the only tooth was found to have two canal. 2. Of the 101 canals studied, 85.1% of the canals were found to have lateral canals and these ramifications were usually located in the apical third of the root. 3. Of the two root canals in one root, 25.4% of the canals were found to have transverse anastomoses and were usually located in the middle third of the root 4. 33.3% of apical foramens were located directly on the root apex and 66.7% of them laterally, and 46.5% of canals showed distal curvature.