Abstract：In order to study the factor and the size of the Gauss normal coordinates error,adopting single factor analysis method,error is analyzed caused by longitude deviation and latitude deviation. The results show that:( 1) influence is relatively large caused by longitude deviation and latitude deviation of Gauss positive operator coordinates for ground point of Gauss plane coordinates,and the size of longitude deviation and latitude deviation should be strictly controlled in the calculation;( 2) the influence of longitude deviation on the y coordinate is relatively large,the difference may bring y coordinate 30. 966 m by longitude deviation 1″ in the six degree belt;( 3) the influence of latitude deviation on the x coordinate is relatively large,the difference may bring x coordinate 30. 757 m by latitude deviation 1″ in the six degree belt. The results of this paper can provide a theoretical basis for the analysis of the size of the coordinate conversion error.

Keyword：Gauss projection;positive operators of coordinates;error analysis;longitude deviation;latitude deviation;