The Yeongju Gaheungdong Petroglyph on the joint plane composed of biotite granite has form o f the hilt-shaped symbols. The rock i s mainly c omposed of quartz, biotite, plagioclase and alkali-feldspars minerals. Considering the analysis of the outcrop containing the Yeongju Gaheungdong Petroglyph, the outcrop are relatively stable. The major deterioration aspects are surface exfoliation, grain peel-off, crack, damages and scribbling. Surface e xfoliation and grain peel-off a re d eveolped by clay m inerals and soluble salt. For conservation of these petroglyphs, study for rock surface conservation and continuous monitoring are necessary.