Cystic fibrosis (CF) and primary ciliary dyskinesia (PCD) in children are both accompanied by copious amounts of infected sputum. Kinesitherapy (KT) eliminates mucostasis by providing bronchial drainage. KT methods are being constantly improved. The purpose of this research was to determine the effectiveness and safety of the new vest airway clearance system (ACS) chest vibration therapy machine model YK800 by Zhengzhou Yangkun Medical Instrument Co., Ltd. (Zhengzhou, China) in children with CF and PCD. The ACS consists of a compressor and a vest and creates high-frequency oscillation of the chest promoting drainage of problematic parts of the respiratory tract, small- and medium-caliber bronchi. Materials and methods used: in a study based on the National Medical Research Center for Children’s Health (Moscow, Russia) the KT included 5 sessions with the Yangkun YK800 in 15 patients aged 5 to 17 y/o: 8 with CF and 7 with PCD. Objective criteria: measurement of external respiratory function (ERF) and saturation, monitoring of chest excursion, and the 6-minute walk test. Subjective criteria: complaints, well-being, comfort. Results: objective criteria - improved ERF indicators in % (FVC p=0.004; r=0.829; FEV1 p=0.023; r=0.973; FEF25% p=0.018; r=0.840; FEF50% p=0.016; r=0.827; FEF75% p=0.015; r=0.867), especially high-speed indicators (FEF25%, FEF50%, FEF75%) that indicate the cleansing of mucus in the medium and small respiratory tracts; saturation improved (p=0.020; r=0.548); chest excursion increased (p=0.002; r=0.779). According to the 6-minute walk test, there was a significant increase in the distance traveled (p=0.000; r=0.535), 13 (86.6%) patients at the end of the course rated it as easier. Subjective criteria - 80% of patients noted sen-sations of productive coughing, easier expectoration of sputum: improvement in general condi-tion - 15, reduction in fatigue - 12, increased physical activity - 12, easier expectoration of phlegm - 13, reduction in episodes of paroxysmal cough - 13. Comfort in the use of the vest was rated at 4.4 points, noting mild vibration. Conclusion: the Yangkun YK800 vest airway clearance system as part of the KT has shown its effectiveness and safety in children with CF and PCD.