A field-aligned potential drop of &PHgr;∥≤100 kV can be produced in the corona due to the loss cone constriction effect on a 0.25 A/m2 field-aligned current driven by the dynamo process in the photosphere under the condition that Nm≥2¿104 cm-3 and Bm≥60 G near the top region of a coronal loop. This condition probably can be satisfied during coronal mass ejections when the coronal loop rises to a height greater than one solar radius. Since coronal mass ejection events are often observed to precede solar flares, the proposed model of field-aligned potential drop can be related to solar flares through coronal mass ejection events. The resulting 100 kV field-aligned potential drop in the corona can accelerate an electron beam to produce nonthermal hard X-ray bursts. The magnetic field produced by the field-aligned current is estimated to be ΔB(0)≈0.3 T at the foot of an erupting coronal loop. The ratio ΔB(0)/B0=1, which is on the high side, but is probably acceptable for coronal mass ejection events of very large spatial scales. ¿ American Geophysical Union 1990