染色体之间的平衡易位，当片段很小或涉及染色体数目多时，显微镜下容易漏诊，或难以准确判定断裂点。本文报告了用染色体荧光原位杂交（ＦＩＳＨ）的实验技术结合常规Ｇ显带、高分辨Ｇ显带技术诊断了２例难辨认的染色体易位。本研究表明，ＦＩＳＨ技术结合细胞遗传学核型分析，对于检测小片段难辨认或复杂的染色体易位是非常有帮助的。 Balance between chromosomes translocations, when the fragment is small or involves a large number of chromosomes, microscopic misdiagnosis, or difficult to accurately determine the break point. This paper reports two cases of chromosomal translocations that are difficult to identify by using experimental techniques of chromosome fluorescence in situ hybridization (FISH) combined with conventional G banding and high resolution G banding technique. This study shows that FISH combined with cytogenetic karyotyping can be very helpful in detecting chromosomal translocations that are difficult to recognize or complex in small fragments.