Based on an analytical solution of the two-dimensional Poisson equation in the subthreshold region.this paperinvestigates the behavior of DIBL(drain induced barrier lowering)effect for short channel 4H-SiC metal semiconductorfield effect transistors(MESFETs).An accurate analytical model of threshold voltage shift for the asymmetric shortchannel 4H-SiC MESFET is presented and thus verified.According to the presented model.it analyses the thresholdvoltage for short channel device on the L/a(channel length/channel depth)ratio,drain applied voltage VDS and channeldoping concentration ND,thus providing a good basis for the design and modelling of short channel 4H-SiC MESFETsdevice.