Abstract: The specialty of reliability for correlative observables is studied.The residual vector can be expressed as a linearization equation of observable's errors and column components of the reliablity matrix (the influence vectors).The correspondence coefficient of the influence vector and the residual vector is used to study on the condition that the observable's error is outlier.In this paper,the theory of correspondence analysis is proposed and discussed.This theory is used to solve the problem of mult outlier analysis in correlative observables.