Using the thin film brick-wall model and WKB approximation,the entropy of the scalar quanti-ty field in the non-stationary and slowly changing Reissner-Nordstr m(R-N)black hole is calculated.

• 采用薄膜brick-wall模型；运用WKB近似；计算了缓变动态Reissner-Nordstr m黑洞的标量场的熵.