I have acidity problem in my stomach.when i rise from sleep my mouth remains full of water, during night i spit my times water coming in my mouth.

You have GERD: You do have gstro esophageal reflux causing your symptoms you can try over the counter medicine like prilosec, Prevacid (lansoprazole) etc follow the directions and if still have symptoms see your doctor also dont eat within 2to3hours of going to bed, avoid foods like citric fruits, spicey food, caffeine, chocolate, mint etc.

Reflux?: If u have acid reflux, mouth may b producing saliva to neutralize reflux in mouth. Can try rx or otc acid blocker (zantac/pepcid/prevacid etc) , not eating before going to bed, elevating head of bed, losing weight (if overweight), avoiding med/food triggers (fatty/fried, acidic, spicy foods). If problem persists, see fp for further evaluation & treatment.