You can deduct travel expenses you incur to earn business and professional income.
Travel expenses include
If you are driving your vehicle to the destination, you must track your kilometers and claim the trip as part of your business use percentage. See Rita's article about claiming vehicle expenses.
If your spouse is on the trip with you and you wish to claim his/her travel costs, your spouse must be active in the business and is there for business purposes.
If there is a business and a pleasure component to the trip, (ie the trip is five days and three of the days are personal), you can claim the travel there and back and any other travel costs. However, the meals and accomodation expenses can only be claimed for the days you were away for business purposes.
A business purpose to a trip could be anything, as long as it is valid. You could be checking out a new supplier or establishing a new downline. It could be for attending a convention, or going to a meeting. Be prepared to have good documentation to prove that it was a business trip (especially if to a resort destination eg Las Vegas or Hawaii - especially if the trip is in January - Brrrr!!) CRA is looking for a detailed daily itinerary of your business activities while you were travelling for business. If you are at a convention or meetings, keep all the agendas and notes that you took with your tax documents.