The Technological Pedagogical Content Knowledge (TPCK) framework has been adopted by many educational technologists and teacher educators for the research and development of knowledge about the pedagogical uses of Information and Communication Technologies (ICT) in classrooms. While the framework is potentially very important, efforts to survey teachers' TPCK efficacy has yet to identify all seven factors postulated by the framework. This study attempted to validate a TPCK efficacy survey by implementing it on an Asian group of 550 preservice teachers from China, Hong Kong, Singapore and Taiwan. The seven factors underlying the TPCK framework were identified which suggested the research instrument to be valid and reliable. The structural equation model proposed based on the TPCK framework supported eight out of 12 hypotheses about the relationships between TPCK constructs. The results indicate that the positive effects of the basic knowledge factors of CK, PK, and TK were indirect, occurring through the second layer of knowledge factors (TPK, TCK, and PCK). Implications for preservice teacher professional developments are discussed. (Contains 2 tables and 2 figures.)