A brake fluid pressure control device for a vehicle capable of performing fluid pressure control of a brake fluid pressure applied to a wheel brake , the brake fluid pressure control device comprising: wheel speed acquisition means that is configured to acquire a wheel speed; slippage amount calculation means that is configured to calculate a slippage amount of a wheel ; and bad road determination means that is configured to determine whether a state of a traveling road surface is bad, wherein the bad road determination means is configured to determine whether the state of the traveling road surface is bad using a value related to wheel behavior calculated based on at least the wheel speed (VW) and a bad road determination threshold value (TH), and to change the bad road determination threshold value (TH) according to the slippage amount (SR) of the wheel , characterized in that the bad road determination means is configured to: change the bad road determination threshold value (TH), when the slippage amount (SR) of the wheel is more than a predetermined value (P), to a value larger than the bad road determination threshold value (TH) in the case where the slippage amount (SR) of the wheel is equal to or less than the predetermined value (P), and change the bad road determination threshold value (TH), when the state in which the slippage amount (SR) is equal to or less than the predetermined value (P) continues for a predetermined time or more, to a value smaller than the bad road determination threshold value (TH) in the case where the slippage amount (SR) is more than the predetermined value (P). wheel speed acquisition means that is configured to acquire a wheel speed; slippage amount calculation means that is configured to calculate a slippage amount of a wheel ; and bad road determination means that is configured to determine whether a state of a traveling road surface is bad, wherein the bad road determination means is configured to determine whether the state of the traveling road surface is bad using a value related to wheel behavior calculated based on at least the wheel speed (VW) and a bad road determination threshold value (TH), and to change the bad road determination threshold value (TH) according to the slippage amount (SR) of the wheel , characterized in that the bad road determination means is configured to: change the bad road determination threshold value (TH), when the slippage amount (SR) of the wheel is more than a predetermined value (P), to a value larger than the bad road determination threshold value (TH) in the case where the slippage amount (SR) of the wheel is equal to or less than the predetermined value (P), and change the bad road determination threshold value (TH), when the state in which the slippage amount (SR) is equal to or less than the predetermined value (P) continues for a predetermined time or more, to a value smaller than the bad road determination threshold value (TH) in the case where the slippage amount (SR) is more than the predetermined value (P). change the bad road determination threshold value (TH), when the slippage amount (SR) of the wheel is more than a predetermined value (P), to a value larger than the bad road determination threshold value (TH) in the case where the slippage amount (SR) of the wheel is equal to or less than the predetermined value (P), and change the bad road determination threshold value (TH), when the state in which the slippage amount (SR) is equal to or less than the predetermined value (P) continues for a predetermined time or more, to a value smaller than the bad road determination threshold value (TH) in the case where the slippage amount (SR) is more than the predetermined value (P). <EOS>