Objective To study the clinical value of percutaneous dilational tracheostomy(PDT) in the critical patients. Methods 56 critical patients who needed mechanical ventilation hospitalized in ICU were enrolled and divided into two groups: PDT group ,25 cases and 0T groups ,31 cases. The length of incision wound, duration of operation, amount of haemorrhage, complications were observed. Results The operation time was significantly shortened [(9.9±3.4)minutes vs (27.2 ±5.1)minutes],blood loss was significantly decreased[(5.2±2.2)ml vs (18.2±3. 5)ml] ,size of operation incision was significantly shorter[(15.0 ± 1. 6)mm vs (41.2 ±3.9)mm],lacking oxygen time was significantly shorter [(10.2±2.1) seconds vs (31.1 ±6.2) seconds] in PDT group compared with OT group (all P＜0. 01). PDT had less subcutaneous emphysema and incision bleeding in PDT group than those in OT group (all P＜0.05). Conclusion PDT was easier in performance with less complication,and was deserved to apply in critical patients.