一秒率（forced expiratory volume in one second/ forced vital capacity，forced expiratory volume in one second/ vital capacity，forced expiratory volume in one second/ forced expiratory volume in six seconds），呼吸病学名词，第1秒用力呼气容积与用力肺活量、或与肺活量或与6秒用力呼气容积的比值。一般用/FVC表示。是最常用的判断有无气流阻塞的参数。