Room impulse response is one of most important information with localization of sound source in 3D audio. Actually we can adjust the distance and spaciousness of a sound source with impulse response of the room. Through consequent experiments, we found that C80 and EDT are varying systematically with sound source distances, and these variations are due to early reflection decay curves. This paper contains brief explanation of the two parameters as auditory distance cues, shaping of early reflection decay curves for control of auditory distance, and psychological test results of auditory distance control with early refection decay curve shaping. With these validations, we can confirm early reflection decay curve shape is effective factor for control of perceptual auditory distance and spaciousness in the room.