Abstract: Objective To investigate the hypophosphatemia in patients with chronic hepatitis B (CHB) and hepatitis B-induced liver cirrhosis （LC） during nucleos（t）ide analogs （NUCs） treatment. Methods The patients with CHB and LC in our hospital from March 2012 to March 2015 was retrospectively analyzed. The serum phosphorus levels was routinely detected and hypophosphatemia was defined as<0.82 mmol/L for at least two times at the interval of 2 months. The Logistic analysis was estimated by SPSS21.0 installation packages for the factors of hypophosphatemia. Results 318 patients （197 CHB and 121 LC） were recruited in this study, and 217 of them took adefovir dipivoxil（ADV） alone or in combination with other NUCs and 101 took other NUCs without ADV. The occurrence of hypophosphatemia in patients with CHB was 11.7%,no significant difference to 10.7%（P>0.05） in patients with LC;Twenty （15.9%） out of one hundred and twenty-six CHB patients with ADV treatment had,while 3（4.2%） out of 71 without ADV had hypophosphatemia（x²=5.83,P<0.05）;11（12.1%）had hypophosphatemia in 91 patients with LC taking ADV,while 2 out of 30 without ADV had hypophosphatemia（x²=0.29,P>0.05）;8 （24.2%）out of 33 patients younger than 35 yr-old had hypophosphatemia, while 3 （9.1%）out of 33 older than 55 yr old had hypophosphatemia;Logistic analysis showed that gender （OR=7.36,P=0.007）and taking ADV（OR=3.51,P=0.015）were the risk factors of hypophosphatemia. Conclusion The clinician should take consideration that young adult patients taking ADV might have hypophosphatemia.