SnO

2

nanoparticles were synthesized by the sol-gel method

then the crystal structures and morphology of the nanoparticles were characterized by scanning electron microscopy and X-ray diffraction. The results show that these particles are pure SnO

2

in the nanoscale range. Then these SnO

2

nano-particles are used as source materials to make resistance type gas sensors. The gas sensitivity(referring to working temperature-sensitivity and response-recovery time)of the SnO

2

nano-particles to CH

4

at the volume fraction of 2.5×10

-4

is tested at different working temperature. The results show that the highest sensitivity of SnO

2

nano-particles at working temperature of 350 ℃ to CH

4

is 11

and the response-recovery time is 5 s and 8 s

respectively. The experiment results show that the rapid response and high sensitivity of the gas sensor made from the SnO

2

nano-particles has important utility value in the industrial safe operation and environmental protection.