This study evaluates the protective effects of Korean garlic juice against the toxicity of methyl mercuric chloride (MMC) in relation to fetal ossification in pregnant Fischer 344 rats. This study has as its basis, both theory and data that neutral amino acids in garlic juice have protective effects against mercury poisoning. Pregnant rats were dosed in various combination with 20 mg MMC/kg body wt. and 0.5 or 1.0 garlic juice/kg body wt. on the 7th day of gestation. Fetuses were extracted from the dams on 20th day of gestation, and the fetal bones were stained and measured. The results obtained are as follows: 1. Fetal body weights, body lengths, and head length were significantly decreased by as much as 23.5%, 21.3%, 15.5% respectively in 20 mg/wt kg methyl mercuric chloride groups (p<0.05). But in the garlic treated groups, they were almost similar to the controls. 2. The ossification centers were significantly decreased by as much as 35.1% in pelvic phalanges, 53.5% in pectoral phalanges, 74.1% in ternebrae, 76.2% in tail in 20 mg/wt kg methyl mercuric chloride groups (p<0.05). But in the garlic treated groups, they were significantly increased by as much as $81.2{sim}88.7%$ and $94.8{sim}98.9%$ of controls. 3. The ossified pectoral girdles were significantly decreased by as much as 66.6% in clavicle, and in other areas $74.2{sim}87.4%$ in the 20 mg/wt kg methyl mercuric chloride groups (p<0.05). But in the garlic treated groups, they were significantly increased by as much as $81.2{sim}88.7%$ and $94.8{sim}98.9%$ of the controls. 4. The ossified pelvic girdles were significantly decreased by as much as 57.1% and 56.1% in two ischium, $67.2{sim}81.7%$ in metacarpals in the 20 mg/wt kg methyl mercuric chloride groups (p<0.05). But in the garlic treated groups, they were significantly increased by as much as $67.0{sim}85.6%$ and $90.1{sim}98.7%$ of the controls. 5. The ossified terenebrae were unchanged or significantly decreased; 0.0% in 5th, 54.1% in 1st, 83.9% in 2nd, 75.0% in 3rd, 72.7% in 4th, 79.8% in 6th of 20 mg/wt kg methyl mercuric chloride groups (p<0.05). But in the garlic treated groups, they were significantly increased by as much as $29.5{sim}55.1%$ and $54.5{sim}84.0%$ of the controls. 6. The ossified ribs were significantly decreased by as much as $8.3{sim}18.0%$ in 20 mg/wt kg methyl mercuric chloride groups (p<0.05). But in the garlic treated groups, they were significantly increased by as much as $87.1{sim}93.5%$ and $96.3{sim}99.7%$ of the controls. In conclusion, Korean garlic juice significantly protected against the toxicity of MMC in relation to the fetal ossification in pregnant rats.