This paper presents an extensive study geotechnical factors controlling undrained shearing characteristics of Quseir Varigated Shale in central part of Dakhla Oasis. The clayey soil of Quseir Shale covers the floor of Dakhla Oasis. In recent years, the size of structures in this region has been increasing. The shearing behaviour of soils is of major concern for engineers, since the solution of stability problems in foundation engineering requires knowledge of the shearing strength of the underlying soil. The Quseir Shale in Dakhla Oasis consists of four layers (green gypsiferous shale graded downward into yellowish green shale, green shale and reddish gray shale). The clay minerals of the studied soil consisting of five species namely kaolinite was the predominant clay mineral present, smectite, illite, illite-smectite mixed-layer, and chlorite which arranged in a decreasing order of abundance. The geotechnical parameters of the studied clayey soils show a strong mutual relation between some measurements and undrained shearing parameters. The measured major stress (1) has a close direct proportional relation with sand%, silt%, kaolinite%, calcium carbonate content and depth. The effective cohesion (C) has a close direct proportional relation with clay fractions, initial water content, and smectite%.