Objective To investigate the application of computer radiography system in combination with high kV radiography technique to diagnose cardiac disease.Methods 30 patients with cardiac disease were taken chest photographs,which chest photographs by CR system and high kV radiography technique were compared with these by common high kV radiography.Results The good rate of air tube occupied is 98% in therapy group,but the rate is only 70% in common group.The discrepant comparison is significant differences.Conclusion It is more significant that CR system in combination with high kV radiography technique than common photograph to diagnose cardiac disease.