Laryngopharyngeal reflux (LPR), the backflow of gastric acid into the larynx and hypopharynx, is a contributing factor to hoarseness, throat clearing, throat pain, and globus sensation. The therapeutic effect of proton pump inhibitors (PPIs) is controversial because a high placebo effect can be observed. Sodium Alginate is an effective medication indicated for symptomatic treatment of gastroesophageal reflux. This randomized, double-blind, placebo-controlled study aims to evaluate the efficacy and safety profile of sodium alginates oral suspension (50 mg/ml) 20 ml 3 times daily for the treatment of with LPR patients in Taiwan. Efficacy assessments include mean reduction in the total reflux symptom index (RSI) score after 4 and 8 weeks treatment, mean reduction in the total reflux finding score (RFS) after 4 and 8 weeks treatment, mean changes in the total numbers of reflux episodes as measured by 24-hour ambulatory combined impedance-pH monitoring after 1 day and 8 weeks treatment. Safety assessments include incidence of adverse events. The study hypothesis is sodium alginate is superior over placebo in relieving LPR symptoms.