The subject innovation is primarily provided with a snowboard, seukiyi, ankle protection means in more detail is to protect the wearer's ankle, such as during wearing sport boots relates to a sport boot liner for wearing at the time of performing a sport, such as skate Cozaar is to provide a sports boot liner. That is, the subject innovation is part the wearer's ankle contact of the conventional fiber, but again such as configuration ankle protection means (2) to be applied to sport boot liner (1) consisting of an inner surface portion (1a) of the liner (1) There, and an air pump 9 to air tube element 3 is connected to the air hose 7, the air cylinder sheet 3 ankle rear concatenation unit 5 and the ankle side concatenation unit 6 is heat-adhesive that the bar, characterized in that is configured to be formed divided by the bonding portion 4, after the wearing in the inside of sports boots worn at, according to the present invention carried out mainly enjoy snowboarding, seukiyi, skates, etc. during the winter to use sports boots the ankle synaptic sites for the liner (1) the air cylinder sheet (3) to the ankle protection means (2) performs the air buffer against external impact, made of ankle beep is that the injury factors such as certainly prevented than in the non-drawn will be.