Objective:To explore the concentration of serum calcium in herpes zoster neuralgia（HZN）patient and the relevance between the concentration and the pain degree.Methods:All of the 44 patients in our pain department from August 2015 to September2016 were collected into herpes zoster group

who were diagnosed with herpes zoster neuralgia（HZ group

n=44）.Then the 44 patients were divided into mild pain group（n=10）

moderate pain group（n=26）and severe pain group（n=8）according to their different pain degree.While 40 patients on P.E.who were diagnosed with no herpetic infection were collected as control group（C group

n=40）.A retrospective study on the data of serum calcium as well as the degree of pain was conducted.Results:（1）The concentration of serum calcium of HZ group were lower than that of control group [（2.28±0.09） mmol/L vs.（2.38±0.05） mmol/L

t =5.720

P =0.000].（2）There was a significant difference in number of patients with different pain degrees between different calcium levels in HZ group.With the decrease of the serum calcium level

the number of patients with pain degree beyond moderate was on the increase

while that of patients with mild pain degree was on the decrease.（3）In HZ group

it demonstrated a negative correlation between the level of serum calcium and pain degree（r=-0.50

P=0.001）.（4）In HZ group

serum calcium level of mild pain group was higher than that of moderate pain group[（2.37±0.09）mmol/L vs.（2.26±0.08）mmol/L

P=0.010].There was a significant difference of serum calcium level between mild pain group and severe pain group [（2.37±0.09）mmol/L vs.（2.23±0.07）mmol/L

P=0.010].Conclusion:During the stage of herpes zoster

the concentration of the serum calcium is decreased.The pain degree is depended on the level of serum calcium.With the decreasing of serum calcium level the pain degree is on the increase.