The subcommittee on superalloys and coatings, for The Society for Materials and Science, Japan was established in 1997. For the committees’ second stage work, we recommenced a fundamental study on thermal barrier coatings (TBCs). In this study, we would like to introduce our activities. In particular, relationships between coating conditions and coating properties were discussed. We used 4 spraying conditions such as; 1) standard condition, 2) larger particle used and lower velocity, 3) normal particle used and lower velocity, and 4) standard condition and heating up the substrate to 200 ^oC. Each sample was sprayed by one of the above conditions, and evaluated in a round robin test. Porosity ratio, residual stress, and bonding strength etc. were evaluated by several techniques for the specimens. As a result, we indicate some recommendations for evaluation of fundamental properties of the plasma sprayed TBCs.