Abstract: In the great investigation of territorial resources，a large number of copper，lead and zinc polymetallic ore （area） points，such as Lawu copper-zinc polymetallic ore，Youqialang silver-lead ore and Yaguila lead-zinc ore etc..were found and evaluated by Henan Institute of Geological Survey in Nyenchen Tanglha Mountain Area in Tibet.In order to expand the prospecting achievements of the area，the 10-乙1 Pb-Zn-Ag polymetallic anomaly of 1∶500 00 stream sediments survey around Gema Village was verified.The prospecting target area was reduced by soil geochemical and magnetic survey；the location of mineralized bodies was delineated （inferred） by geological route mapping；the hidden orebodies were tracked by IP intermediate gradient measurement method；the orebodies were revealed by exploration trenching engineering；the spatial distribution of polarized body was determined by arranging IP sounding section perpendicular to the mineralization zones；finally，a medium-sized Pb-Zn polymetallic deposit was found in the study area by geological drilling verificaiton.The prospecting mode of finding and evaluating Pb-Zn polymetallic deposit in Gulu-Youkaxiang Pb-Zn-Ag metallogenic belt with adverse natural conditions was summarized.It has certain reference value for the prospecting and exploraiton study in similar areas.

Key words: Pb-Zn-Ag polymetallic deposit, Stream sediment survey, Trenching, IP intermediate gradient, IP sounding, Prospecting target area