In current study, we aim to discuss effect of Ligasure Small Jaw Instrument on hypocalcemia prevalence decrease in thyroidectomy patients. One hundred and fifty patients with thyroidectomy indication, who will be admitted in surgery wards of Tabriz Taleghani and Emam Reza hospitals from March 2014 till March 2015, enroll our study. All patients take part in case or control group by their own willing, as they choose surgery method on their own, and some will receive Ligasure Small Jaw and others Clamp and tie method.( P less than 0.05 is statistically significant) Sampling is non-randomized and census and patients candidate for thyroidectomy such as thyroidectomy cancers will enroll our study. All patients will be visited one day, one week and 6 week after operation, in order to evaluating their complications after surgery such as: vocal cord paresis, hematoma, hemorrhage,wound infection, and chronic pain. This examinations will be done by a surgeon, and data will be recorded carefully.