Objectives: Periodical revision of regular surveys is inevitable and essential to keep or to raise their efficiencies through making necessary improvements in designing process and application of available methods, usually such improvements or adjustments could affect the Comparability of the data time series so that it may not permit such comparability easily.It is important to note, however, that despite the benefits of improving current survey, changes should be approached cautiously and the effects measured and evaluated. When possible, methods to bridge differences caused by changes or techniques to avoid the disruption of historical series should be included in the testing of new or revised survey. The present study aims to ensure the comparability of Unemployment rates from the two Labour Force Surveys (2005 and 2006) and the Household’s Employment and Unemployment Characteristics Surveys (2002 to 2004) by adjusting such rates based on the standard definitions. Method: The methodology that implied in this research is a librarian method. It is based on documents, information and data that Produced and accessible in this area from related resource. Findings: The Household’s Employment and Unemployment Survey is suffering from a considerable overestimation in unemployment rate because of sum deference’s between its definitions and international standard definitions, mostly caused by lack of care for the criterion "Seeking work" in the survey implementation and processing its results and undercount employed with work house of 16 or less and self employed in agriculture sector. Comparison of the adjusted rates in the years from 2002 to 2006 is indicative of reasonable increase in Unemployment rate in 2005 and 2006 as compared with the preceding years. The extent of such an increase is not observable on the basis of figures released from the two surveys in the years mentioned. Results: As a result of using different definitions and criterias for dividing work age population to employed, unemployed and inactive in new and old surveys, the resulted unemployment rates by those surveys are not comparable directty. In fact we can compare above rates just after reconstructing them by the same definitions.