Objective To clinical analyze the changes of ocular anterior segment structure using ultrasound biomicroscope(UBM) and their clinical values in blunt eye injury.Methods Sixty-nine eyes with no-opening wound in blunt eye injury were examined by UBM(Paradigm Model P40).Scanning photography of central and 3,6,9,12 clock hour were recorded and printed,other clock hours were scanned if needed.These records were studied with clinical findings.Results UNM findings showed that 27 eyes had hyphema,22 eyes had anterior chamber angle recession,16 eyes had iridodialysis,19 eyes had local luxation of lens,5 eyes had vitreous henia in anterior chamber,19 eyes had cyclodialysis,23 eyes anterior choroidal detachment and 9 eyes had anterior vitreous haemorrhage.Of the 69 eyes,62 eyes had combined structure changes showed above,which account(89.9)%.Conclusions UBM is a practical tool for diagnosis of anterior segment structure changes in blunt eye injury,especially when there are corea opacity,hyphema,cyclodialysis,ocular hypotension and others.It can provide exact informations for the diagnosis and treatment,which can not be showed by routine ocular examination and B-scanning ultrasonography.