TiO2　based　nanosized　powders　doped　with　Mo6+　were　prepared　by　sol-gel　technique　using　TiCl3.　It　indicates　that　rutile　TiO2　can　be　obtained　at　low　annealing　temperature　(400°C).　Oxygen　sensitivity　of　thick-film　sensors　were　also　researched　at　low　operating　temperature　(145°C)　and　1　×　10-4　oxygen　concentration.　The　sensitivity　of　TiO2　doped　with　Mo6+　is　better　than　that　of　pure　TiO2　due　to　the　charge　density　on　surface,　which　is　detected　by　Zeta　potential.