Machinery Repair Plant (MRP) of Erdenet Mining Corporation (EMC) is the subject of this research in order to determine the labor conditions and illnesses of the employees at the metallurgical plant.MRP’s function is to smelting and processing metals for milling, producing, repairing or restoring metal structures of machineries or equipment. MRP employs 639 employees for 185 working places and 568 equals to 88.6% of them have been working n the abnormal condition which reveals that the plant has hard conditions of labor.The research was performed using retrospective research method in fact modeling; and made an evaluation on measurements of 2008-2014, performed by the occupational health laboratory covering 185 working places at MRP; occupational diseases occurred to 639 employees; and perspective status of temporarily invalidity. Electronic logging data base for Occupational Diseases and temporary invalidity at the EMC was used for categorization and conclusion according to the International category of 10 diseases. Research results of labor conditions: As to measurements made between 2008 and 2014 on the working places at MRP, dust concentration reached up to 18mg/m3 and that was excessive than the corresponding average by 9 times of measurements. Results from occupational disease survey: 137 employees have been affected by the occupational diseases at the MRP for the last 27 years. 39, which is a large amount, out of 137 were affected by bronchadenitis caused by dust. Results from temporary invalidity survey: 2293 occurrences were recorded in relation to temporary invalidity at MRP between 2008 and 2012 and the percentage of injuries or toxicities and certain disorders caused by outsources is 15.6%. Reviewing the survey results, common occurrences are bronchadenitis caused by dust, spinal neural inflammations and chronic inflammation caused by dust toxicities, and the large percentages are occupied by temporary invalidity, injuries or toxicities and certain disorders caused by outsources, respiratory organ and system disorders. It shows that those of diseases and disorders are dependent to the working place environments and labor conditions.