It is Chinese size and smaller than the USA size.
Please check the size carefully.
US X-Small=China Small:Length:29.13"(74cm)-33.46"(85cm),Bust:37.80"(96cm),Shoulder:16.14"(41cm)
US Small=China Medium:Length:29.92"(76cm)-35.83"(91cm),Bust:39.37"(100cm),Shoulder:16.54"(42cm)
US Medium=China Large:Length:30.31"(77cm)-36.22"(92cm),Bust:40.94"(104cm),Shoulder:16.93"(43cm)