At present, the intergenerational support of the younger ageing parents in the onlychild families in urban China has the following Characteristics: On the intergenerational economic support, the proportion and quantity of money children giving to their parents exceeds what the elderly parents giving to them. The intergenerational economic support in the only child families is more balanced than in the multiple children families. On the intergenerational support in housework, there is more support in the only child families than in the multiple children families, but again the former is more balanced. In terms of spiritual support, the proportion of the ageing parents of only children feeling closer is higher than that in multiple children families. Between the only sons and the only daughters, there is no significant difference between the economic support and the spiritual support, but the support in housework is significantly different. The intergenerational support of the younger ageing parents in the only child families is mainly influenced by the status of their only child and the intergenerational relationship.