Abstract: Southwestern Hunan Province lies in the junction belt of Yangtze Plate and South China fold system，with deep and large faults running through the whole area，mantle-derived magma activity is strong，and the distribution of basic-ultrabasic rock in Qingbaikouan strata （Xuefengian） are grouped and zoned.Prospecting work of nickel deposit is carried out in Longcheng in Togndao County，abundant prospecting information is obtained，concealed nickel mineralized belt with the thickness of 61.66 m and average TNi grade of 0.1％is discovered.By studying the petrography，geophysics，geochemistry and nickel mineralization characteristics of Longcheng basic-ultrabasic rock belt，and comparing them with the known ore-bearing rocks in Baotan Area in Guangxi Province.The study results show that:①ultrabasic rock is the cause of magnetic anomalies，the nickel-bearing ultrabasic rock have the physical combination characteristics of “three high and one low” （high magnetism，high density，high polarizability and low resistivity），which is the important geophysical indicators for the prospecting of nickel deposit；②w（∑REE） and w（La）/w（Lu） values of the independent diabase are 2~2.5 times of marginal diabase，w（∑REE） and w（La）/w（Lu） values of surface diabase are both lower than others，w（∑REE） is about 50×10-6，w（∑REE） is （20～30）×10-6，it can be regarded as geochemical indicator for the prospecting of nickel deposit；③the nickel deposit is controlled by high differentiation pluton，the ultrabasic pyroxene peridotite and peridotite zones are nickel mineralized zones，and penetrated orebodies may appear in the deep part.Based on the above discussion results，further analysis results indicated that the prospecting ideas of nickel orebodies in Southwestern Hunan Province can be summarized as:the known nickel mineralization belt in Longcheng Area can be firstly verified by deep drilling engineering，prospecting target area can be delineated by ground magnetic survey work，based on rare earth testing results to select the dikes （bodies），therefore，metallogenic prediction and location of nickel orebodies can be done effectively by means of the combination method of gravity，magnetic and electrical geophysical sounding.

Key words: Nickel sulfide deposit, Basic-ultrabasic Rock, Concealed nickel mineralized orebody, High differentiation pluton, Penetrated orebody, Prospecting indicator, Metallogenic prediction