Wegscheiderite is a.n anhydrous alkali carbonate mineral which was first found in Green River basin of Wyoming, U. S. A. as a new mineral, and in China was first found at Biyang basin, Henan province, in 1982. The chemical composition of this mineral is sodium carbonate and sodium bicaxbanate, and the chemical formula is Na2C03.3NaHCO3. The crystal is plate-shaped, color- less, and transparent, occurring mainly in alkali ore stratum composed of nah- colite. Different methods of identification have been performed on the minera lsamples.It is determined as follows: The mineral is biaxial(-)，and the indi- ces of refraction are:Ng =1 .531, Nm=1.524, Np=1.435; 2V=31.45º (talc.); Cell parameters: a=10.046, b=15.633, c=3.492,。a=92º8', β=95º42', γ= 108º34'. The strongest lines in the powder diffraction pattern are; 3.70 (35)， 2 .97 (100)，2.67 (41)，2.213 (60).The principal infrared absorption bonds are;2616, 1692, 1662, 1359, 1048, 1018, 839, and 677cm-1. From the characteristics of occurrence and association, wegscheiderite is formed in continental carbonate lake which is rich in sodium and higher in pco2，under h馆hex temperature and fast evaporation.