Wax　deposition　of　diesel　oil　and　contamination　of　gasoline　by　diesel　wax　deposit　is　a　severe　problem　in　sequential　transportation　of　product　oil　in　pipes.　However,　it　has　long　been　neglected　by　the　pipeline　transportation　industry.　In　response,　this　work　aims　to　present　a　unique　perspective　on　wax　deposition　of　diesel　oil　and　consequent　contamination　of　gasoline.　A　cold　finger　apparatus　was　designed　and　constructed.　Model　oil　composed　of　diesel　and　refined　wax　was　prepared　for　wax　deposition.　Shear　dispersion　was　excluded　for　wax　deposition　of　diesel　oil.　Moreover,　dissolution　experiments　of　diesel　wax　deposit　in　gasoline　were　conducted.　It　was　found　that　the　dissolution　rate　increases　with　oil　temperature　and　decreases　with　cold　finger　temperature　and　shear　stress.　Analysis　on　gasoline　quality　after　diesel　wax　deposit　dissolution　indicated　that　contamination　of　gasoline　caused　by　diesel　wax　deposit　severely　deteriorates　its　distillation　range,　but　the　octane　number　remains　acceptable.　This　work　features　an　interesting　investigation　on　the　wax-deposition　mechanism　of　diesel　oil,　dissolution　characteristics　of　diesel　wax　deposit,　as　well　as　quality　deterioration　of　subsequent　gasoline.　It　would　be　helpful　in　scheduling　a　product　oil-transportation　program.