By taking the lamprophyres and pyrites from the Laowangzhai orefield, Yunnan Pro vince as the starting materials, exper iments were made the liquid immiscibility of laprophyresulfide melt at high te mpe rature and high pressure 1.5～3.0 GPa and 1162～1560℃ in the DS29A cubic 360 0t/6 type high pressure apparatu s. The results show that the liquid immiscibility of the lampropyresulfide mel t may occer during the early stage of magmatic evolution （under highpressu re conditions）, but may occur in all stages of the magmat i c evolution （from highpressure to lowpressure condition） if there exi sts sulfur. T he sulfide melt which is separated from the lamprophyro melt will make dir ectional mov ement in the temperature and preesure fields and gradually in the lowtemperatu re and lowpressure region. As the density of sulfide melt is higher than that of lamprophyre melt, the former would accumulate at the bottom of the magma chamber and there would be a striking boundary between the two melts.