【Objective】Soil reclamation/cultivation will sure affect soil environment of the saline-alkali soils involved and cause changes in soil quality. Therefore, it is necessary to explore or characterize changes in soil quality of the saline-alkali soils different in year of cultivation for reasonable utilization of saline-alkali soil resources.【Method】In this study, soil samples were collected, separately, from the topsoil (0~20cm) and subsoil (20~40cm) layers of farmlands, under the same wheat/maize crop rotation system, but different in year of cultivation (< 5 a, 10 ~ 15 a, 20 ~ 25 a, 30 ~ 35 a and 50 ~ 60 a), in the saline-alkali soil region of the Yellow River Delta. The samples were analyzed from the aspects of soil physics, chemistry and biology, for bulk density, organic matter, total nitrogen, available phosphorus, readily available potassium, total salt, pH, sucrase and alkaline phosphatase, a total of nine soil quality indicators. On such a basis, principal component analysis was performed, SQI (Soil quality index) calculated and variation of soil quality in the farmland with years of cultivation evaluated quantitatively. 【Result】Results show that soil quality improved with cultivation going on. Compared with virgin wasteland, the farmlands cultivated for < 5 a, 10 ~ 15 a, 20 ~ 25 a, 30 ~ 35 a, and 50 ~ 60 a were 36.97% ~ 161.49% and 164.44% ~ 444.40% higher in SQI of the 0 ~ 20 cm and 20 ~ 40 cm soil layers, respectively. SQI varied in increasing rate from period to period. Compared with the virgin wasteland, the farmland increased by 36.70% and 164.44% in SQI, respectively, in the 0 ~ 20 cm and 20 ~ 40 cm soil layers during the initial period of the cultivation (<5 a) and by 38.27% and 18.18% during the period of 10 ~ 15a of cultivation; by 10.37% and 39.35% during the period of 20 ~ 25 a of cultivation as compared with that during the period of 10 ~ 15 a; by 24.42% and 24.79% during the period of 30 ~ 35 a of cultivation as compared with that during the period of 20 ~ 25 a of cultivation; and by 0.74% and 0.17% during the period of 50 ~ 60 a of cultivation as compared with that during the period of 30 ~ 35 a of cultivation. And SQI began leveling off after 30 ~ 35 a of cultivation. The 0 ~ 20 cm soil layer was 65.69%, 93.85%, 53.53%, 53.08% and 86.95% in SQI than the 20 ~ 40 cm soil layer, respectively, in the farmland cultivated for <5 a, 10 ~ 15 a, 20 ~ 25 a, 30 ~ 35 a and 50 ~ 60 a.【Conclusion】All the findings in this study demonstrate that crop cultivation improves soil quality, and the effect varies with the cultivation going on. It is, therefore, advisable to conduct comprehensive scoring based on principle component analysis so as to objectively and efficiently evaluate soil quality of farmlands different in year of cultivation.