The aim of this study was to investigate effects and mechanisms of electroacupuncture (EA) on blood glucose and insulin sensitivity in mice fed with a high fat diet. Methods: Both wild type (WT) and adipose Ecto-nucleotide pyrophosphate phosphodiesterase (ENPP1) transgenic (TG) mice were fed with high-fed diet for 12 weeks; each mouse was studied intra-peritoneal glucose tolerance test (IPGTT) and insulin tolerance test (ITT) with or without EA at abdomen or auricular areas. Results: 1). High fat diet induced insulin resistance in both WT and TG mice. 2). In the WT mice, EA at 3Hz and 15Hz but not at 1Hz or 100Hz via CV4+CV12 significantly reduced postprandial glucose levels; EA at 3Hz was most potent. The glucose level was reduced by 61.7% at 60 min and 74.5% at 120 min with EA at 3 Hz (all P<0.001 vs. control). 2) Similar hypoglycemic effect was noted in the TG mice; 3) on contrary, EA at auricular points increased postprandial glucose level (P<0.03). 4). EA at 3Hz via CV4+CV12 significantly enhanced the decrease of blood glucose after insulin injection, suggesting improvement of insulin sensitivity. 4). Plasma free fatty acid was significantly suppressed by 42.5% at 15 min and 50.8% at 30 min with EA (P < 0.01) in both WT and TG mice. Conclusions: EA improves glucose tolerance in both WT and TG mice fed with high fat diet, and the effect is associated with stimulation parameters and acupoints, and is probably attributed to the reduction of free fatty acid.