Microextraction by packed sorbent (MEPS) is a new miniaturized form of solid-phase extraction and it is a green sample pretreatment technology. MEPS has been widely accepted and used by several research groups online or offline as a sample preparation technique before instrument analysis. MEPS reduces the sample handling time and organic solvent consumption. MEPS is suitable for small sample volumes and can easily be connected with different chromatographic techniques without modification. The sorbent bed in MEPS is integrated into a liquid handling syringe that allows for low void volume sample manipulations either manually or in combination with laboratory robotics. MEPS is a simple, fast and robust sample preparation technique with several advantages, miniaturization, automation, fast operation course, on-line coupling with analytical instruments and low-cost operation with less solvent and low sample consumption. Sorbent type, device, and matrix are important factors in MEPS research and applications. The performance of MEPS has recently been illustrated by online with liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry assays for pharmaceutical, environmental, and food analyses. This paper deals with MEPS device-optimized sorbent, sample matrix, and application. The progress and potential development of the technique are also discussed.