Fresh shrimp (Penaeus monodon) was treated by either high pressure processing (HPP) or heat for comparison. The changes of water states and distribution were detected by low field nuclear magnetic resonance (LF-NMR). Relaxation times T2 and distribution areas were calculated and compared to investigate the treatment effects on shrimp samples. Pressure levels of HPP ranged from 100MPa to 600MPa, and pressure holding time was set as constant, i.e. 10min. The initial temperature of pressure transient medium was 25℃, while 40, 60 and 90℃ were selected and the treatments time was set as 10min during heat treatments. For both HPP and heat treatments, treatment conditions of untreated control samples were at 0.1MPa and 25℃. Experimental results showed that both HPP and heat treatment could alter, to some extent, relaxation times T2 and relative contents of different states of water in shrimp samples. A kind of bound water with high capacity of combining with macromolecules in meat was induced when samples were treated at pressures in excess of 100MPa or at temperatures in excess of 60℃, with relaxation time located between 0.1ms and 1ms. The content of combined water in meat, which was highly related to product water holding capacity, was significantly influenced by heat treatment but not by pressure. The content of combined water decreased significantly with the temperature rising. The changes of combined water content after HPP and heat treatments suggested that HPP was a superior method for producing fresh shrimp to retain the water holding capacity than heat treatment.