Changes in firmness and pectin contents during maturation and sotrage of Stsuma mandarin (Citrus Unshiu Marc. var. miyagawa) were investigated. Firmness of fruits was decreased quickly from 1,176.8g-force to 503.6g-dorce. Satsuma mandarin was stored at 3$^{circ}C$ and 85%${pm}$5% relative humidity. Firmness were decreased from 538.9g-force to 336.9g-force during storage. Alcohol-insoluble solid(AIS) of peel and flesh were decreased quickly from 27.04g/100g to 12.30g/100g, and from 2.67g/100g to 1.91g/100g during maturation of fruits. During storage of fruits, AIS of peel was decreased from 14.32g/100g to 12.06g/100g . During maturation of fruits, water soluble pectin (WSP) of peel were increased from 420.82mg/100g to 601.62mg/100g as wet basis. Hexametaphosphate soluble pectin (HMP) was also increased from 450.17mg/100g to 577/53mg/100g. hydrochloricacid soluble pectin (HSP) was decreased from 1938.30 mg/100g to 695.14mg/100g. During storage of fruits, HMP and HSP of peel was decreased from 507.82mg/100g to 695.14mg/100g. During storage of fruits, HMP and HSP of peel was decreased from 527.82mg/100g to 275.47mg/100g , and from 672.28mg/100g to 351.36mg/100g, respectively. WSP of peel was increased from 543.70mg/100g to 584.31mg/100g. Total pectin substance (TPS) of peel was decreased from 2809.79 mg/100g to 1874.29mg/100g during maturation, and from 1723.80mg/100g to 1211.14mg/100g during storage, respectively. Composition ratio of pectin was in order of WSP>HSP>HMP.