The purpose of this study is to evaluate the castability of Ni-Cr alloys for crown and bridge. New young, Hi-Crown and CB-80 which are widely used in dental laboratory were chosen, casting and increased the temperature of furnace 100$^{circ}C$ of each 7 grades from 600$^{circ}C$ to 1200$^{circ}C$. The results are as follows : 1. CB-80 is the most prominent castability among the three Ni-Cr alloys which are Hi-Crown, New-young and Hi-Cr. 2. The good burning temperatures of casting for CB-8p are 900$^{circ}C$, 100$^{circ}C$ and 1100$^{circ}C$ which are obtained four complate casting body of five former patterns. 3. The most proper burning temperature for three Ni-Cr alloys is 900$^{circ}C$.