Objective To probe the reasonable range of central lymph node dissections(CLNs)for papillary thyroid carcinoma (PTC) in cN0 T1/T2 by analyzing the metastasis regulations of PTC in cN0 T1/T2.Methods Data of 891 PTC patients in cN0T1/T2 cases according to the research criterion from Oct.2013 to Sep.2017 were analyzed.All the patients were under the treatment of the same group of surgeons in Department of Thyroid Surgery of the First Affiliated Hospital of the Kunming Medical University and had undergone operation of bilateral total resection of thyroid gland and central lymph node.The clinical and pathological data were collected.Univariate and multivariate analysis were used to investigate the risk factors of central neck lymph node metastasis and high volume central neck lymph node metastasis.Results ①Univariate analysis showed that gender (P=0.002),age(P=0.002),multiform(P=0.000),nodular goiter(P=0.000)and with Hashimoto's(P=0.031)had significant influence in prevalence of CLN node metastasis.Gender(P=0.010)and tumor size(P=0.000)showed significant influence in prevalence of high volume CNL node metastasis.In multivariate analysis,age (OR=0.962,OR=2.856)and nodular goiter(OR=0.969,OR=3.012)showed the independent risk factor of CNL node metastasis and high volume CNL node metastasis.②The numbers of lesion in unilateral lesion were not correlated with IpsiCLNs and Cont-CLNs metastasis (P=0.347,P=0.653).The tumor diameter was correlated with Ipsi-CLNs and ContCLNs metastasis (P=0.010,P=0.000).The tumor diameter of bilateral multifocal carcinoma was correlated with LN-prRLN-CLNs metastasis (P=0.019).The tumor diameter of left and right unilateral single focal lesion was not correlated with LN-prRLN-CLNs metastasis(P=0.684,P=0.072).Conclusions According to the study,it is recommended that the PTC in cN0 T1/T2 should routinely undergo preventive central lymph nodes dissection in the case of technical support:①Preventive overall CLND is recommended for unilateral non-microscopic carcinoma and bilateral multiform carcinoma,especially in those older than 55.②For patients with unilateral single or multifocal microscopic carcinoma,only ipsilateral central lymph nodes dissection can be considered.③ Generally,routine dissection is not necessary for the lymph nodes of the right recurrent laryngeal nerve in the central region of the neck.However,for bilateral non-small cancers and right non-small cancers,LN-prRLN-CLNs dissection is recommended.