Adjustbale pet fence in vehicle

A pet fence comprising:

• a first part having multiple first bars transversely connected thereto;
• at least two second parts each having multiple second bars transversely connected thereto, a width of each second part being smaller than a half width of the first part;
• at least two positioning tubes each having first holes defined therethrough, multiple second holes defined through each of the at least two positioning tubes and located at an angle relative to the first holes;
• multiple adjustment units each having a first member, a second member and a third member, each adjustment unit cooperatively coupled to a locking unit which extends through one of the first holes of one of the at least two positioning tubes, the first member, the first part, the second member, one of the two second parts and the third member to connect one of the at least two second parts to the first part, and when the locking unit is loosened, the at least two second parts are movable relative to the first part;
• and
• at least one clamp unit having a connection tube and an attachment member, a fixed clamp connected to one end of the connection tube, a movable clamp connected to the fixed clamp and adapted to secure the at least one clamp unit to a headrest rod of a seat of a vehicle, the attachment member located between the positioning tube and the connection tube, the connection tube and the attachment member connected to the second holes of the at least two positioning tubes.