In this paper, we investigated the end-to-end performance of a dual-hop variable gain relaying system over mixed fading environment. In such environment, the wireless links of relaying system undergo different fading conditions, where one link is subject to the Nakagami-m fading, the other link is subject to the composite Nakagami-lognormal fading which is approximated by using mixture gamma fading model. Based on the cumulative distribution function of the end-to-end signal-to-noise ratio (SNR), some novel closedform expressions of the average end-to-end SNR, the outage probability, the symbol error rate and the ergodic capacity for the dualhop variable gain system are derived, respectively. Then, some approximate analysis and the diversity order are found based on the above new expressions in high SNR region. Finally, numerical and simulation results are shown to verify the accuracy of the theoretical analysis.