We propose an adaptive redundancy control method for erasure-code-based real-time data transmission over the Internet. The loss rate is an important quality of service (QoS) parameter for real-time data transmission. However, real-time data transmission over best-effort networks, such as the Internet, suffers from a frequent packet loss due to traffic congestion. Erasure-code-based loss recovery scheme is widely used for loss recovery on the Internet. We propose a redundancy estimation algorithm which considers consecutive losses since the loss recovery rate depends on the amount of redundancy data. A continuous time Markov chain is used for modeling the loss process and adjusting the number of redundant packets. Measurements and simulation results show that the proposed scheme can be used as an efficient loss recovery algorithm for real-time data transmission over the Internet.