Pulse of up to 1000 seconds with 0.5 MA plasma current is the main objective of EAST (Experimental Advanced Superconducting Tokamak) [S. Wu, ¿An Overview of the EAST Project,¿ <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Fusion Eng. Des.</i> , vol. 82, pp. 463-471, Oct. 2007] discharge experiments. For long duration discharge, real-time diagnostics is indispensable. To meet the requirement, a slice-based data acquisition system for long duration discharge has been designed and developed. This paper gives an overview of this system. The slice-based data acquisition system is based on time slice mechanism, which divides continuous experimental data into slices. And the slice data are transferred, stored, published in real-time during collecting. Moreover, the introduction of multi-stage storage and time window greatly enhanced the speed of mass data access. The slice-based data acquisition system has been reliably operated in the EAST experimental campaigns.