Accommodation reservation revenue for the first quarter of 2022 was RMB1.5 billion (US$229 million), representing an 8% decrease from the same period in 2021, and a 24% decrease from the previous quarter, primarily due to the continued disruptions resulting from the COVID-19 resurgence in China.
Transportation ticketing revenue for the first quarter of 2022 was RMB1.7 billion (US$262 million), representing a 10% increase from the same period in 2021 and a 10% increase from the previous quarter, primarily driven by strong recovery of air travel in the oversea market.
Packaged-tour revenue for the first quarter of 2022 was RMB124 million (US$20 million), representing a 27% decrease from the same period in 2021 and a 30% decrease from the previous quarter, primarily due to the continued disruptions resulting from the COVID-19 resurgence in China.
Corporate travel revenue for the first quarter of 2022 was RMB222 million (US$35 million), representing a 12% decrease from the same period in 2021 and a 40% decrease from the previous quarter, primarily due to the continued disruptions resulting from the COVID-19 resurgence in China.
Cost of revenue for the first quarter of 2022 was relatively stable at RMB1.1 billion (US$168 million) comparing to the same period in 2021. Cost of revenue decreased by 5% from the previous quarter. Cost of revenue as a percentage of net revenue was 26% for the first quarter of 2022.
Product development expenses for the first quarter of 2022 decreased by 11% to RMB2.0 billion (US$311 million) from the same period in 2021 and decreased by 12% from the previous quarter, primarily due to a decrease in product development personnel related expenses. Product development expenses as a percentage of net revenue was 48% for the first quarter of 2022.
Sales and marketing expenses for the first quarter of 2022 decreased by 11% to RMB843 million (US$133 million) from the same period in 2021 and decreased by 35% from the previous quarter, primarily due to a decrease in expenses relating to sales and marketing promotion activities. Sales and marketing expenses as a percentage of net revenue was 21% for the first quarter of 2022.
General and administrative expenses for the first quarter of 2022 decreased by 15% to RMB584 million (US$92 million) from the same period in 2021 and decreased by 20% from the previous quarter, primarily due to a decrease in general and administrative personnel related expenses. General and administrative expenses as a percentage of net revenue was 14% for the first quarter of 2022.
Loss from operations for the first quarter of 2022 was RMB359 million (US$55 million), compared to loss from operations of RMB787 million for the same period in 2021 and loss from operations of RMB704 million for the previous quarter. Adjusted EBITDA for the first quarter of 2022 was RMB91 million (US$16 million), compared to RMB-216 million for the same period in 2021 and RMB54 million for the previous quarter. Adjusted EBITDA margin was 2% for the first quarter of 2022, compared to -5% for the same period in 2021 and 1% for the previous quarter.
Income tax benefit for the first quarter of 2022 was RMB14 million (US$2 million), compared to income tax expense of RMB41 million for the same period in 2021 and income tax expense of RMB37 million in the previous quarter. The change in our effective tax rate was primarily due to the combined impacts of changes in respective profitability of our subsidiaries with different tax rates, certain non-taxable income or loss resulting from the fair value changes in equity securities investments and exchangeable senior notes, and changes in valuation allowance provided for deferred tax assets.