This paper intends to review the qualifications of arbitrator, the disclosure of disqualifications by arbitrator, the challenge grounds of arbitrator, and the challenge procedure of arbitrator under the arbitration laws and rules. There are no provisions for the qualification of arbitrator in the UNCITRAL Model Law on International Commercial Arbitration. Under the UNCITRAL Model Law on person shall be precluded by reason of his nationality from acting as an arbitrators. Under the UNCITRAL Model Law when a person is approached in connection with his possible appointment as an arbitrator, he shall disclose any circumstances likely to give rise to justifiable doubts as to his impartiality or independence. An arbitrator, from the time of his appointment and throughout the arbitral proceedings, shall without delay disclose any such circumstances to the parties. Under the UNCITRAL Model Law an arbitrator may be challenged only if circumstances exist that give rise to justifiable doubts as to his impartiality or independence, or if he does not possess qualifications agreed to by the parties. Under the UNCITRAL Model Law the parties are free to agree on a procedure for challenge an arbitrator. Failing such agreement, a party who intends to challenge an arbitrator shall send a written statement of the reasons for the challenge to the arbitral tribunal within 15 days after becoming aware of the constitution of the arbitral tribunal or any circumstance that give rise to justifiable doubts as to his impartiality or independence. Unless the challenged arbitrator withdraws from his office or the other party agrees to the challenge, the arbitral tribunal shall decide on the challenge. In conclusion, an arbitrator has a responsibility not only to the parties but also to the process of arbitration, and must observe high standards of conduct so that the integrity and must observe high standards of conduct so that the integrity and fairness of the process will be preserved.