A short cavity Er/Yb fiber grating laser is demonstrated. Its resonant cavity is composed by two Bragg gratings which were UV written directly on a 30 mm photosensitive Er/Yb fiber. The two gratings were ～6 mm and 10 mm long, with 90% and 98.6% in reflectivity, 0.28 nm and 0.26 nm in 3 dB bandwidth, respectively. Pumped by a 980 nm diode laser, the associated fiber grating laser exhibits 8 mW thershold, ～14% slope efficieny, 30 dB polarisation mode suppression ratio. About 6 mW output power and 61 dB signal to noise ratio were obtained upon the maximum 50 mW 980 pump power in the experiment.