Software reliability problem was observed in early days of computing. Some of the errors in the software are hidden for a long time. This observation became the basis for reliability of software. Various SRGMs have been suggested to solve the problem of reliability, out of which Ant Colony algorithm is an improvement on the traditional methods as the probability of getting a solution is one for various data sets. Even though Ant Colony algorithm method gives higher estimation accuracy for most of the models compared to PSO it needs some modification to improve on accuracy. In this paper, the authors are present an improved Ant Colony algorithm for estimation of parameters.