Plastic film mulched furrow-ridge cropping is a recent modification of maize cropping pattern. By excluding evaporation, redistributing precipitation from ridges to furrows and increasing soil temperature, plastic film mulched furrow-ridge pattern can significantly enhance maize grain yields and thus it has been widely extended on semiarid Loess Plateau for maize production. However, the sustainability of soil fertility, and related soil managemental practices have been limitedly studied under continuous application of this cropping pattern. This research was therefore designed to investigate effects of plastic film mulched furrow-ridge maize cropping on soil organic carbon pools and the possibility of introducing the soil incorporation of maize straws into this cropping pattern. The research site (35°54'N, 104°05'E) was located at Xiaokangying, Yuzhong County of Gansu Province, with an altitude of 2013 m and annual precipitation of 388 mm. The experimental design included four treatments, namely, nil-straw incorporation plus nil-mulch (control), straw incorporation (S), film mulch (M), and straw incorporation plus film mulch (S+M), with 3 replicates on a furrow-ridge micro-relief-prepared field. The experiment started in March 2009 and ended in October 2010. In addition to the measurement of maize grain yields, soil samples were taken from the top 15 cm layer at sowing and harvesting in each experimental year for determinations of total soil organic carbon, particulate organic carbon (particle size 2-0.005 mm) and light organic carbon (density <1.8 g/cm³) concentrations. Soil microbial biomass carbon and activities of β-glucosidase, alkaline phosphatase and urease were also periodically analyzed for the top 15 cm layer under different treatments through maize growth season each year. Compared to control, M and S+M treatments improved maize grain yields by 89%-105% and 93%-136%, whereas S treatment did not affected maize grain yields. Over two years, total soil organic carbon concentration was not changed by S, M or S+M, compared with control. However, M inclined towards decreasing but S or S+M treatment showed increasing, particulate organic carbon and light organic carbon concentrations in soils. The increasing effect in particulate or light organic carbon pool with S+M treatment was more significant when compared to M than compared to control. Soil microbial biomass carbon and activities of β-glucosidase, alkaline phosphatase and urease were increased by S, M or S+M, compared to control. The increasing effect in soil microbial biomass carbon or activities of three enzymes with S+M treatment was more significant when compared to S or M. Further, soil β-glucosidase, alkaline phosphatase and urease activities all positively correlated to soil microbial biomass carbon concentration over treatments and periodical measurements for two experiment years, respectively. Our preliminary results showed although plastic film mulched furrow-ridge cropping markedly increased maize grain yields but may have a potential to decrease soil organic carbon pool; it was feasible to introduce maize straw into this cropping system for a favorable soil organic carbon balance and microbial activity.