Kim shot a bogey-free round and totaled 5-under 139 heading into Sundays finale of the 54-hold event.
She leads Hee-Won Han of South Korea (69) and Karen Stupples of England (70), who had four birdies in her opening 10 holes.
With this wind, I didnt make any bogeys out there, Kim said. The last birdie was something else.
Katherine Hull of Australia, who led by two shots after the opening round, struggled with a 76 and fell three strokes back. The Australian had an opening-round 66.
American Paula Creamer had a bogey-free round of 69 to trail by five shots. Defending champion Suzann Pettersen of Norway also shot a bogey-free 69, seven shots off the lead.