2-Bromopropane (2-BP) is considered as a kind of environmental endocrine disrupters (EDs). Its reproductive and hematopoietic toxicity has aroused the attention of international toxicologists during the past five years.In the present study, we aimed to determine experimentally the testicular toxicity of 2-BP in male rats. Materials & Methods Forty SD male rats were divided into four groups of 10 rats each. The rats were intra-abdominally administered 2-BP once per day for 5 days continuously at the doses of 1800 mg/kg, 600 mg/kg, 200 mg/kg and normal saline, respectively. The rats were dissected one week after the first administration. Results The body weight, absolute testes weight and relative testes weight of the rats in 1 800 mg/kg dose group decreased significantly with comparison to those of the con- trol group,while the weight of accessory gonads showed no significant change. With the increase of dosage, the seminiferous tubules damage rate aggravated while the ratio of spermatogonia in total germ cells fell with P<0. 05. The seminiferous tubule area of rats in 1800 mg/kg group also reduced significantly. Under light microscopic examination, the spermatogonia of administered rats showed degeneration and chro- matin condensation. The nucleus of spermatocytes appeared hyperchromatic and py- knotic.Obvious testicular damage could be found in rats of high dose group, including large amount of spermatogonia necrosis or loss and reduced spermatocyte number. The electron microscopic findings were similar to those of the light microscopy, except that typical morphological change was found in the middle dose group: the structure of spermatogonia was destroyed, mitochondrion and endoplasmic reticulum scattered outside, nucleus disintegrated; some of the spermatocytes’ membrane became nuclear, chromatin condensed and cogulation necrosis appeared; the nuclear membrane of round spermatids also showed slight damage. Conclusion The results indicated that testis was the target organ of 2-BP’s reproduc- tive toxicity. The testicular toxicity of 2-BP started from damaging spermatogonia and its damage on spermatogonia was most obvious among all germ cells. 2-Bromopropane (2-BP) is considered as a kind of environmental endocrine disrupters (EDs). Its reproductive and hematopoietic toxicity has aroused the attention of international toxicologists during the past five years. The present study, we aimed to determine experimentally the Testicular toxicity of 2-BP in male rats. Materials & Methods Forty SD male rats were divided into four groups of 10 rats each. The rats were intra-abdominally administered 2-BP once per day for 5 days continuously at the doses of 1800 mg The rats were dissected one week after the first administration. Results The body weight, absolute testes weight and relative testes weight of the rats in 1 800 mg / kg dose group decreased significantly with comparison to those of the con- trol group, while the weight of accessory gonads showed no significant change. With the increase of dosage, the seminiferous tubules damage rate aggravated while the ratio of spermatogonia in total germ cells fell with P <0. 05. The seminiferous tubule area of ​​rats in 1800 mg / kg group also reduced significantly. Under light microscopic examination, the spermatogonia administered rats showed degeneration and chro- matin condensation. The nucleus of Spermatocytes were hyperchromatic and py-knotic. Obvious testicular damage could be found in rats of high dose group, including large amount of spermatogonia necrosis or loss and reduced spermatocyte number. The electron microscopic findings were similar to those of the light microscopy, except that typical morphological change was found in the middle dose group: the structure of spermatogonia was destroyed, mitochondrion and endoplasmic reticulum scattered outside, nucleus disintegrated; some of the spermatocytes’ membrane became nuclear, chromatin condensed and cogulation necrosis was; the nuclear membrane of round spermatids also showed slight damage. Conclusion The results indicated thattestis was the target organ of 2-BP’s reproducive toxicity. The testicular toxicity of 2-BP started from damaging spermatogonia and its damage on spermatogonia was most obvious among all germ cells.