Among investment for dental casting, we selected 4 kinds of investment(2 Gypsum-bonded and 2 Phosphate-bonded) and prepard 120 specimen by dividing into two cast of using Ring and Ringless case from $0^{circ}C$ to $30^{circ}C$ at interval of $10^{circ}C$ to invest in fluence on the fitness of casting body according to the liquid temperature of Gypsum-bonded and Phosphate-bonded investment. The result was as follows; 1. Gypsum-bonded investment showed best fitness at $30^{circ}C$ representing difference of singnificance in order of $20^{circ}C$, $10^{circ}C$, and $0^{circ}C$, From the difference of investment, Deguvest was proved superior than Cristobalite. 2. Phosphate-bonded investment showed no severe difference at $10^{circ}C$ and $20^{circ}C$, but showed better fitness at $10^{circ}C$, representing difference of significance in order of $0^{circ}C$, $30^{circ}C$, difference of significance was shown between investment also. 3. In Ringless investing method, there were no difference of significance in Deguvest CF and Unovest. 4. When using a Ring with a Sheet of asbestos liner installed, there was some difference of significance representing superiority of Ringless investing method.