Physico-chemical qualities of pyunyuk depending on the cooking time were evaluated to produce high quality and to reduce labor and processing time. Pork headmeat divided into two parts was cooked for 1~4hrs, trimmed and pressed with 110kg/$ extrm{cm}^2$(gauge pressure) for 3.5hrs at 1$0^{circ}C$. The contents of general nutrients, yield, texture, color, fatty acid composition, gel structure, and sensory evaluation were observed. Deboning time was very dependent on cooking time. Optimum cooking time observed in this study was 2~2.5hrs for efficiency of deboning and yield. Excess cooking time resulted in low yield and working efficiency. Yield variation depending on the cooking time was 14.3~26.0% and it was reduced by increasing the cooking time. The content of moisture was 53.5~54.8% which was not significantly different by cooking time. The content of crude fat was 14.2~26.0% which was decreased by increasing the cooking time. The contents of crude protein(21.1~26.3%) and mineral(1.4~2.7%) were increased by increasing the cooking time. The color of pyunyuk was significantly different by cooking time(p<0.05). In the texture, hardness and chewiness of the pyunyuk cooked for 2hrs were significantly higher than others processed in this study(p<0.05). However cohesiveness and springiness were not different among pyunyuks. With sensory evaluation, hardness was similar among the pyunyuks cooked over 2hrs. The pyunyuk cooked for 1hr showed higher value in juiciness than the pyunyuk cooked for 3~4hrs(p<0.05). The % of saturated fatty acids was decreased by increasing the cooking time, and gel structure of pyunyuk cooked for 2hrs was the most compact among treaments. In conclusion, 2hrs was proper as a cooking time concerned with working efficiency and physico-chemical quality of pyunpyk.