This study was investigated on effect of implant system about investment condition and burn out temperature. Posterior bridges were fabricated by using plastic sleeve and gold sylinder. The results were as follows; In plastic sleeve test and fitting cast copings. the phosphate bonded investment showed better gypsum bonded investment. The pure special liquid showed better margin fitness compared with mixed liquid (special liquid + distilled water). In gold cylinder test. the good burn out temperature of Ceramic PFG and Crown Gold was evaluated $0^{circ}C$ to $820^{circ}C$ and was decreased on $780^{circ}C$ for 30 minutes. $0^{circ}C$ to $750^{circ}C$ and was decreased on $650^{circ}C$ for 30 minutes.