Packet loss rate is one of the basic network performance metrics. However, current measurement methods conflict with measuring precision and costs. A self-adaptive sampling based loss rate measurement method was proposed in this paper. By utilizing the characteristics of delay-loss correlation and loss-loss correlation, it dynamically adjusts probing period adaptively, under the indications of larger delay samples and loss events in measuring process on burst losses. Consequently, it improves the measuring accuracy without the dramatic increase of probing costs. Simulation results have shown that a good trade-off is obtained in this method. When compared with ping, it gets much lower errors with a minor increase of probing costs; and compared with BADABING, the errors are similar, but it greatly decreases probing costs.