The specially created trial issue will be inserted in copies of the London paper that are sold at mainline and underground train stations on June 9.
As well as features on issues such as potty training babies from birth, modern manners in young children and an interview with celebrity chef Hugh Fearnley Whittingstall on his children's eating habits, it also offers readers discounts on future issues and has a 16-page London section, looking at attractions in the capital for families.
Junior editor Catherine O' Dolan said: "This special edition of Junior will give parents across London and the south east a taster of what the magazine has to offer on a monthly basis."
Lindsaye Fox, group publisher at Future, added: "Offering a special issue of Junior with the Evening Standard was a perfect way of getting Junior out to a wider audience.
"With the shift of society towards older parents with established careers, Junior appeals to parents who demand the best for their children."
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