///Observation of cores from wells such as TS1 and others which have drilled into the Cambrian dolomite indicates that there are plenty of pores which are some millimeters to some centimeters in size and were were though to be developed in surface -karst environment. Some of the Cambrian dolomite was buried to a depth more than 8 000 m. Characteristics of well logs and seismics suggest that the karst dissolution of the Cambrian dolomite took place contemporaneously or penecontemporaneously during deposition due to exposure caused by fall of relative sea level and that there was not strong tectonic uplift. There are always some minerals such as dolomite and quartz filling in vugs of the Cambrian dolomites in the well TS1 and others. The filling dolomite shows curved crystal surface and wave extinction. The maximal frequency of the homogenization temperatures of the fluid inclusions in the filling dolomite is between 110 - 130 ℃and the homogenization temperatures do not increase linearly with depth.